Archives of an email list on the history of binoculars. http://www.europa.com/~telscope/binoc_list.txt home page: http://home.europa.com/~telscope/binotele.htm 1-49 I am forming an e-mail list on the subject of binoculars. Topics of discussion will include: --Evaluation, testing, and use of both old and new binoculars. --History of binoculars. --Optics and mechanics of binoculars. --Hand held and giant binoculars, twin telescopes, battery commander's scopes, field glasses, and any other binocular telescopes, from the years 1600-2000. --Buying & selling binoculars (My feeling is that we should restrict it to 'for sale' notices. Most recipients of this list are looking for unusual old glass, and 'wanted to buy' ads would be numerous & unproductive. However, I'm open to the idea of including WTB messages.) Notices of services related to binoculars seem appropriate. I welcome input on other topics that would be suitable, or any other detail of running the list. ==================================================================== #1================================================================== Hello Peter et al. EXCELLENT idea of a digest mailing list. I'm on another one for vintage Thunderbirds and it's been a wealth of information. One of the things they did is create an archives of postings that is catalogued every few months. This way new-comers can read past postings and avoid asking the same questions over and over. I'll be happy to kick off the mailing list: My name is Randy Pakan, I'm a 45 year old Computer Graphics Technician / Photographer at the University of Alberta, Edmonton, Alberta, Canada. I've been collecting antique cameras and binoculars for about 15 years. I started collecting cameras as an off shoot of being a photographer. I guess it started with realitives saying "I've had this old camera kicking around for years -- do you want it?" I became interested in astronomy and telescope building, and collecting antique binoculars was natural to follow. I've built several award winning telescopes and I have drawn up plans for building 6 inch mirror binoculars. Luckily one of the members in our astronomy club is an optical technician and he can grind a set of mirrors that have identical focal lengths (this is rather critical). Enough babble for now. I hope others will introduce themselves. And I'd love to hear about any experiences in building binoculars. Randy Pakan randy.pakan@___rta.ca ================= Randy is an e-mail acquaintance of mine. From a previous message: "I'm a photographer\digital imaging technician. I'm involved with 3D stereo mapping and various projects that use satellite imagery." Stereo cartography is a source of much useful information on binocular vision, tolerances for alignment, etc. Randy responded to an article of mine at the Amateur Telescope Making Journal web site, 'The Early History of Binoculars', at http://www.halcyon.com/rupe/atmj/issues/issue9/binocular.html (This article has now been expanded into a 45 minute lecture, with over 20 examples of pre-1800 binocular telescopes). The many recent amateur-made reflecting binoculars are of great interest to me, and a spectacular example will be part of my next article for ATMJ. This one is a pair of 5 inch refracting objectives, placed 18 inches apart, in the manner of a battery commander's scope. I neglected to include this subject in my list of suitable topics, and also forgot the very important subject of maintenance & repair of old binoculars. Another response to my first message was from Fred Watson, who is known to most of us as the author of the booklet, "Binoculars, Opera Glasses, and Field Glasses", to this date the only book in the English language on the overall history of binoculars. The other book in English is Steve Rohan's volume on German 10 x 80s of WWII, and he is on the list as well. I will note that Fred's response went directly to the list, because of a failure on my part to configure Eudora correctly, which should be corrected at this point. This was not a problem here, but there are a few reasons for keeping the list a 'digest': traffic on the list could increase to many messages a day, junk mail 'spammers' can be kept off by keeping the list under tighter privacy controls, and occasionally someone will post a huge file (usually an image) that can 'choke' member's e-mail software (we need a policy on posting images, any readers who cannot receive them should let me know). I believe most list members will be glad for a 'digest' of messages, however, I'm open to other ideas. Fred did mention one of the ancillary reasons for having a list, and that is to persuade Hans Seeger, John Gould, Bill Reid, and others to get on e-mail. Randy discussed archives, an optimistic idea at this point, but an excellent resource of the other lists I'm on. For now, the archives will be a text file in my computer (and other recipients will keep one, I'm sure.) We do need a software expert to set us up with the efficient programs for group e-mail and searchable archives, but that person will not be me, so every once in a while I'll post a message to see if we have acquired such a resource. ========================================= I invited Jack Eastman, an optical engineer at Lockheed Martin in Denver and longtime stargazer, & observer at Chamberlin Observatory (20" Alvan Clark), to join us. He starts a thread on near-fatal encounters with binoculars: I have a bino story that almost got me killed a couple of weekends ago. We had our annual auction at the observatory and it was a beautiful day. I decided to ride the bike, probably not the best idea in case I buy an 8-inch brashear or something, but I rode anyway. If I had driven I'd have gone up Santa-fe to Evans and across to D.U. On the bike I went over on Dartmouth thru the back streets to the obs. Well, being a sucker for garage sales, I stopped at one about half-way to the auction, and there they were a set of German tank binos, 10X80. Figuring the guy would want a bunch of bucks for these I almost left, I couldn"t carry these thing on the bike anyhow. He quoted his price--Egad only slightly more than a steak-n- eggs at Dennys. Well it turns out I could carry these on the bike after all (all 18# of them. My saddlebags will never be the same) and since I was closer to the obs. than home, I continued to the obs. thinking I could leave them there and pick them up the next time I drove over. When I showed up I was almost mugged by a half dozen crazed bino hunters, but I did survive and the binos seem in excellent optical condition, the really need cleaning on the inside, but the external optical surfaces were free of scrathes digs etc. I didn't buy the 20-inch Clark, so I did get the binos home OK. ========================================== ======================================= #2: 11/6/97 The list heard from Bob Ariail, preeminent student & collector of early telescopes: From: "Robert B, Ariail" "To my knowledge, those interested in a detailed investigation of binoculars have been somewhat of a 'lonely hearts society' in the past. Your program should allow a productive exchange of ideas, details, and facts for all interested participants." Yes, it's always lonely in the elite classes. Bob added some topics of discussion [and I reply]: "Coated vs uncoated binoculars (advantages, disadvantages, effects of magnification, etc.)" [My feeling is that coatings are an unalloyed joy, but I have read that they can increase scatter, an idea that I am not prepared to accept. Any comments?] "The effects of binoculars on seeing (do binoculars - particularly binocular telescopes effectively provide steadier seeing? -etc.)" [Binocular telescopes do not increase resolution over a monocular instrument, but greatly increase contrast & reduce fatigue over long observing sessions. This most complicated subject is of great interest.] "The age of the observer as related to modern wide-angle binoculars (positives, negatives, etc.)" [As the maximum pupil diameter of the observer decreases with diminishing youth, the dimensions of the ideal binocular do change, to higher magnification or smaller objectives, to produce a smaller exit pupil. But do the wide angle oculars lose utility? One thing's for sure: I wouldn't want all those hormones again just to gain a wider entrance pupil.] ====================================== Subject: M3 Here's a paragraph I wrote in answer to a question about a Wollensak M3: I'd appreciate any additions, corrections, or references: The M3 was a standard US Army binocular of WWII. It was made by B&L, Universal Camera Corp., Nash-Kelvinator, and Westinghouse. The paper I have does not mention an M3 by Wollensak, but that is not surprising, during WWII, binocular production was farmed out to all sorts of odd companies. B&L and other optical giants made most of the optics for the various manufacturers. There were minor differences in weatherproofing, reticles, and possibly some were coated. The M3 incorporated an improvement, a setscrew to hold the eccentric ring objective cell, to keep it from rotating when getting knocked around. The M3 has a 8 degree, 30 min. FOV, an f4.4 objective, and the reticle is graduated in mils (horizontal) and hundreds of yards (vertical). Wollensak is well known in the US as a maker of photographic equipment. They split off from B & L in 1899 to make shutters. They had 1200 employees in 1958, but were bought by Revere and then 3M and were closed in 1972. They made many products for the military during WWII. --Peter ======================================== Subject: Reference material on binoculars. My favorite subject. I have assembled a large collection of photocopied catalogs, articles, manuals, military reports, and other paper concerning binoculars. I accomplished this by trading with other collectors, and it has really paid off for all concerned. If you have any old or unusual paper on the subject, please let me know & I'm sure I can find something of interest to you that will motivate you to send me a copy. All of my paper is available for others to use & copy, but I don't have the time to make copies for everyone of anything they might want. As we all know, there is no book length reference on the general history of the binocular in English. Until one is written, the papers that collectors have accumulated to go with their instruments are all we have.....so let's share it. - -Peter ========================= We have another new member, Larry Gubas, archivist for Zeiss Historica, Lngubas@___com We couldn't do better than this for references on the many interesting instruments made by Zeiss. ========================= ======================================= #3: From American Optical to Zeiss. 11/8/97 ======================================== Subject: our resident Japanese translator I was hoping Charlie would make himself known without needing persuasion. Japanese instruments are very difficult to research, and even the middle level binoculars deserve respect for their optical quality. From: Charles Orzech Fellow Afficionados of Binoculars, I am a professor of religious studies specializing in medieval Chinese Buddhism here at the University of North Carolina in Greensboro. I grew up in an optical family--my father worked for American Optical in Southbridge MA, toward the end of his life as a fusion tech. in fiberoptics. My mother was an inspector in the lens plant. In college I first majored in Astronomy and Astrophysics at U Mass but bailed out of that major after I hit the planetary atmospheres class. My current research is on medieval Chinese Buddhist astronomy. I am an active amateur with a special interest in binoculars and have recently been restoring a Yashima 15X80 45 degree inclined glass from 1945 and a 10X60mm 60 degree inclined glass from Fuji (also WWII, I need a roof prism for it). I am always looking for "big glass" so if any of you have anything you want to part with let me know! Also, if you need Japanese labels on old glass translated I can do it. By the way, a local antique dealer has an M3 in so-so condition for $75. This one is coated and has the decal on the left prism cover "Coated Optics--clean with care." regards, Charlie Orzech (910) 856-0597 ================================================== Subject: American Optical AO traced its beginnings to William Beecher, who in 1833 began making spectacle frames in Southbridge, Mass. A merger in 1869 formed AO. They began making spectacle lenses and ophthalmic optics around 1885. In 1935, they acquired Spencer Lens Co., and began production of AO microscopes, including some extremely fine instruments, notably their petrographic microscopes. In 1942, there were 5,486 employees in Southbridge (the maximum). Other factories were located in Keene, NH; Brattleboro, VT, Cambridge, MA; Frederick, MD; Buffalo, NY; Canada, England, Germany, and Brazil. AO had about 250 affiliated retail outlets in the U.S. Warner-Lambert purchased AO in 1967, Reichert became a partner in 1982, Cambridge Instruments bought the group in 1986 (and bought B & L's optical systems division in 1987), and in turn were acquired by Leica. Spencer Lens made binoculars for the Navy during the WWII era, in 6 x 30, 7 x 35, and 7 x 50 configuration, and some were sold as consumer stock after the war. The Spencer 7 x 50s are distinguished by their slightly oversized prisms, and a field of view that is wider by one half a degree than the standard WWII 7 x 50, with an apparent field of view of 7 degrees, 39 seconds. I believe I have seen Japanese binoculars with the AO imprint. Is there any additional information on AO or Spencer binoculars? References: Padgitt, Donald. A Short History of the Early American Microscopes. London: Microscope Publications, 1975. Warner, Deborah. Optical Manufacturing in the United States. Chapter 6 of J. William Rosenthal, Spectacles and Other Vision Aids. San Francisco: Norman Publishing, 1996. --Peter =============================================== Subject: Zeiss instruments We hear from Larry Gubas, who will be a considerable asset to the group if he isn't swamped with requests for assistance. From: Lngubas@___om I would be happy to participate in the group and do any research needed on Zeiss stuff, although I become more and more convinced every day of the number of unique instruments that they made, especially in WWII. My big function in Zeiss Historica is to identify things and I will be happy to do that for this group as well and follow up with documentation but images via the Internet are very slow and something that I would still prefer to do via snail mail. My cataloged based information is open to everyone. I have lost a lot of my available free time via work and so I have less time for real long letters. I recently indentified a "Dosenfernrohr" for someone in California. It is the older revolving eyepiece telescope that they made before the Starmorbi, Asembi, et al. and it used the "Abbe-Amici" prisms. The head of the Zeiss museum did not know the translation of the name and so could not identify the instrument. I was able to send an english version of the text from a catalog. Do you know of the third Seeger book? It is mostly catalog information from Zeiss military during WW II. I have yet to track a copy down to purchase. Larry ============================================ Subject: Siegried Czapski In response to an earlier e-mail, Larry enclosed a paragraph that he wrote on Czapski, an important optical engineer at Zeiss. Siegfried Czapski: joined the firm on a recommendation from Helmholz in 1884 and quickly evolves into Dr. Abbe's immediate assistant. He works to take the formulas and ideas that Abbe has formed over the two prior decades into specific usable products. He also assisted in the growth of the firm into a quality producer of precision instruments and optical products. Carl Zeiss would be held up as an example of manufacturing prowess in Europe thanks to his work. He became well known as a the author explaining many of the optical and mechanical processes at the firm and was the primary informer to the public and the scientific community with regard to many of the firms discoveries. As Schott glasses became available, he made recommendations for their use to internal scientists. In particular he wrote the articles in the Central Magazine for Optics and Mechanics in the mid-1890's which introduced the prism binoculars and attendant theories of Ernst Abbe to the world. He toured and lectured on the developments within the scientific elements of the firm. He published "The Theory of Optical Instruments after Abbe" in 1893 which he updated with Otto Eppenstein in 1904 and which was updated again in 1924 by Eppenstein and Hans Boegehold. His own scientific output included the Corneal Microscope. Although he was a member of the board of management from the outset, he succeeded Abbe as the guiding spirit when he retired in 1903 and more so on Abbe's death in 1905. However, his participation was not very long in this role since he died soon after in 1907 following severe complications following a simple appendectomy. He outlived his mentor by just slightly more than two years but they were important transitional years that cemented the Stiftung and its way of doing business. ================================= ====================================== #4: Anchors Aweigh. 11/12/97 =========================== From: Earl Osborn osbear@___et.com I'm very glad to be a member of this group and will help in any manner I can. I am truly looking forward to the outstanding opportunities that will come to expand my historical understanding of these wonderful instruments. First of all I will introduce myself. While my business is Osborn Optical Systems, I will be here to learn and assist others, not solicit work. I have almost 24 years in the field of optical instrument repair, restoration, and custom design for the U.S. Navy, Army, and Air Force, various goverment agencies, museums and a half dozen commercial concerns. While the majority of the instruments that I work on are of the binocular type(several hundred per year) from 4x23 to over 40x180, I also work on virtually anything with a lens, prism, or mirror. That is; rangefinders, gunsights, submarine periscopes, navigation and surveying equipment, night vision, microscopes, and many, many others from practically every optics country on the planet. While I have gained an extensive background in the fabrication, design, and materials from as far back as the late 1780's up to many current R&D programs, I am lacking in much of the history of the makers and manufactures of these wonderful instruments. I will be more than happy to help anyone in the group to the extent of my knowledge, so feel free to contact me. If I am a day or two slow at responding, please be patient, I subcontract for quite a few companies that claim to do optical work. A clarification on the Spencer 7x50 binocular information. The objective prism is indeed slighly larger than rest of the standard U.S. military 7x50 prisms. But the eyepiece prism is slightly smaller. Also the collective lens and eyelens are larger as well. Spencer also made microscopes under their own name for a while. The third Seeger book is indeed a reprint of the Zeiss spec sheets. Deutsche Optik in CA. (1-800-225-9407) has the book (Tell Mike I said "hi"). [@___.] To all; take it easy, God Bless, and remember, "Optics is Light work". Earl Osborn ====================================== Subject: Navy Optical Facilities We currently have at least 3 ex-opticalmen on the list. One of the areas of history that is right at the edge of being lost is the tradition of Navy training schools & facilities for optical repair. There are some very fine instruments that were known only to Navy circles, including some of the binoculars, and especially the fire control rangefinders built into the big ships. I am fortunate to be friendly with a specialist in the repair of these instruments, Jim Rose, retired civilian chief of the Long Beach Naval Shipyard Optical Shop. Below is an excerpt from my next article for the "Amateur Telescope Maker's Journal", entitled 'Rangefinders and Stereoscopic Telescopes'. (There is also a paragraph on a new amateur made binocular telescope,with 5 inch objectives, spaced 18 inches apart, in Arizona.) Battery commander's telescopes are my absolute favorite optical tool; with enhanced depth, the views are beautiful. If you want to read the whole article, you'll just have to subscribe. The ATMJ is published by Bill Cook, another ex-opticalman (and list recipient), and the web site is: http://www.halcyon.com/rupe/atmj/ --Peter ================================================== Subject: Rangefinders Truly remarkable instruments were used by the U.S. Navy (among others,) from prior to WWI through the 1980s, for controlling the large guns of their ships. Some of these rangefinders used coincidence sighting, where two images were brought together in the viewfinder and the distance read off a scale. Others were stereoscopic rangefinders that gave a true stereo image of the target. A reticle for each eye was fixed in the tube, and formed a stereo image that appeared to move towards & away from the observer when optical wedges were rotated. When the image of the reticles (an arrangement of diamond shapes,) seemed to be at the distance of the target, the actual distance to the target could be estimated. There was extensive research and development on these fire control instruments during the 1920s, and they were the primary tool used to aim naval guns through most of this century. The longest recorded distance for optical rangefinder controlled gunfire, successfully firing on a moving target from a moving battleship, is 26,400 yards, achieved in 1940 by the British. These rangefinders were designed around a particular gun, and the distances at which they were accurate were determined by the range of the gun. In the U.S. Navy, the Mark 41 (1930s) and Mark 75 (1950s) had objectives eleven feet apart, a near focus of 1200 yards, and maximum useful range of 20,000 yards. These were made by Keuffel & Esser, weighed about 1200 pounds, and had 147 glass elements, including lenses, prisms, wedges, reticles, mirrors, and frosted elements. There were 15 foot models, weighing about 1500 pounds, in a motorized mount that was connected with servos to a gyroscope, to maintain the horizon at a level. The 11 and 15 foot models could be targeted on aircraft, and longer instruments were used to range ships and targets on shore. Larger models were made by Bausch and Lomb, including the 26.5 foot used with the common 16 inch guns. The Mark 52 consisted of a 25 power system with objectives 46 feet apart, weighing 10,500 pounds and costing about $100,000 during World War II. Near focus was 5,000 yards, maximum use at 45,000 yards. One interesting aspect of later rangefinders is that they were gas charged with helium, since it is the only gas with an index of refraction that does not change in the temperature range encountered by these instruments, and the extreme length of the rangefinders mandated this stability. Helium can leak through steel, and necessitates yet another level of maintenance for personnel. These instruments were closely held secrets during their era (still used in foreign fleets,) and their size and weight ensured their dismantling on retirement. Very few persons have had the privilege of viewing through one, and the effect can only be imagined. =================================== Request: I've been told that there was a discussion (in 1997) on the newsgroup rec.guns on rangefinders, that included a detailed message from a repairman. I can find no such topic in searches in 'Deja News'. If anyone can point me to these, I'd appreciate it. --Peter =================================== Subject: Reference material on binoculars. Yes, my favorite subject again. The Navy is getting out of the optical business in a big way. Like all military branches, in optical repair the paper trail of an instrument, a procedure, or a facility is typically massive, detailed, and thorough, being designed to prevent culpability in case of foul up. Probably most of the manuals, blueprints, instructions, receipts, and assorted paper is gone by now. However, collectors & optical repairmen are the ones most likely to hear of mothballed tooling, auctions at shops, and the general dispersal of these facilities. Please make it a point to ask about paper whenever you hear of the sale of military optical surplus. Try to contribute to this list, since any useful procedures, details of instrument development, or history of a facility, would be of great interest. Not just U.S. Navy, but any branch of the military of any country. --Peter =================================== Subject: Seeger Book From: DeutOptik@___om Per Larry's inquiry, we have Hans' new book entitled German Military Technology: The Optical Equipment. It's basically a compendium of data sheets put out by Carl Zeiss-Jena from 1930-1940 on optics and instruments produced by them for the Third Reich. They are $100 plus five bucks shipping and all are signed with date of publication. For more info, see the back inside page of our current Deutsche Optik catalogue (issue 16) or call us at 1-800-225-9407. For those inquiring, issue #16 is in the mail with lots of neat new stuff. -- Deutsche Optik ====================================== ================================= Binocular List #5, 11/12/97: Books on Binoculars ================================== Subject: Books It is impossible to explain why there is such a lack of reference material on binoculars. For over a hundred years, they have been a common accessory, with wide applications, and many very critical uses. However, there are only two books in English on the history of binoculars, one on a particular instrument and one a brief introduction. There are several historical books in German, and one in Polish; reminding us that there is a world of resources outside the English language texts. This is the bibliography of books known to me. Please send in corrections & additions. 5 books are for sale by Deutsche Optik, 800-225-9407, so noted. D.O. also carries Hans Seeger's new work, a collection of offprints from Zeiss on their military optical instruments of WWII, including 13 pages of binoculars ($100.) ---------------- Akin, Al. Optics for Birders. Prescott: Wolfe Publishing, 1994. Hale, Alan. How to Choose Binoculars. Redondo Beach: C & A Publishing, 1991. Henson, Truman. Binoculars, Telescopes, and Telescopic Sights. N.Y.: Greenburg Publisher, 1955. Paul, Henry. Binoculars and All Purpose Telescopes. N.Y.: Amphoto, 1980. Piaskowski, Antoni. Dawne Lunety I Lornetki W Zbiorach Polskich. Warsaw: Nakladem Autora, 1996. Reichert, Robert & Else. Binoculars & Scopes. N.Y.: Chilton. 1961. Robinson, Leif. Outdoor Optics. N.Y.: Lyons & Burford, 1989. Rohan, Steve. Eyes of the Wehrmacht. Bradbury: Rohan Optical Press, 1996. [D.O. $50] Seeger, Hans. Feldstecher: Fernglaser im Wandel der Zeit. 1989; Borken, Germany: Bresser Optik, 1989. [D.O. $75] Seeger, Hans. Militaerische Fernglaeser und Fernrohre. Hamburg: Seeger, 1996. [D.O. $120] Seyfried, J.W. Choosing, Using, & Repairing Binoculars. Ann Arbor: University Optics, 1995. [D.O. $20] (The Binoculars, A Module on Waves, Physical Geometrical Optics.) Physics of Technology. N.Y.: McGraw-Hill, 1975. (60p) Von Rohr, Moritz. Die Binokularen Instrumente. Berlin: Springer, 1920. Watson, Fred. Binoculars, Opera Glasses, and Field Glasses. Buckinghamshire: Shire, 1995. [D.O. $10] ============================================= Subject: New book by Dick Buchroeder List participant Dick Buchroeder is an optical engineer in Tucson who has begun work (as co-author) on a book entitled "Giant Binoculars", to be published by Willman Bell. It will focus on recent commercial and amateur made binoculars of 4 inches and greater aperture, with limited discussion of military and historical instruments. Technical aspects, including optical design & theory, will be covered (without undue complexity). The goal will be "providing a handsome book of photographs and diagrams, but also to raise, substantially, the understanding of commercial designers so that the quality of new instruments can be enhanced." Currently, an outline for the book is being drafted, and Dick has asked opticians, amateur astronomers, and this list for feedback on the topics listed below, and others that should be included. Comments can be addressed directly to him, but to the extent that they are of general interest, send them to the list as well. Any one of these could elicit an extensive discussion on this list, and all thoughts will be appreciated. Tentative outline for "Giant Binoculars": l. Why binoculars? 2. Why not just beamsplitter-binoculars that use only a single objective.? 3.Brief history of binoculars 4.Stereoscopic effect & depth perception. 5. False stereo from decollimation and aberrations. 6. Reversed stereo 6.5. Is it possible to get correct perspective except at 1X? Why do images appear, stereoscopically, as they do? 7. Night-time fainter stars? 8. Refractive type 9. Reflective type l0. Catadioptric type 11. Military incentives and ideas for binocular development 12. Rangefinder types 13. Commercial 'twin telescopes' 14. What are the 'names' historically? Who made them. 15. WWI 16. WWII 17. Current commercial stuff (Fujinon, Kowa, Vixen, etc.) 18. Home-made binoculars 19. Materials for optics 20. Materials for supporting the optics 21. Tolerances on manufacture and assembly, and collimation. 22. Effects of bad tolerances and misalignment. 23. Use of mirrors to join the optical axes to the eyes 24. Use of prisms to do that. 25. Prism types...Porro, Pechan, Schmidt, etc. 26. Indirect image paths and ghost images, as well as images of internal parts of the tubes, images from the observer's head, eyelashes, nose, etc. 27. How to baffle; paint, baffle disks, tricks with prisms, etc. 28. Unique problems with special prisms 29. Eyerelief. 30. Interchangeable eyepieces and power-changers (zoom barlows). 31. Turret eyepieces. 32. New developments. 33. Exterior paint, keep them cool or warm, as required. 34. Mounting of the Instrument: portable and fixed. 35. Serviceability / modularity of the equipment. 36. Field alignment / collimation. 37. Finders for binoculars. 38. Color correction: achromats vs apochromats. 39. Carrying cases and shipping containers. Caging components against damage in shipment. 40. Problems in the tropics or other humid environment. 41. Giant refractors 42. Fixed ocular, movable objective designs. 43. Adjustment for +/- diopters. 44. What practical issues would you like to see discussed 45. What theoretical issues? 46. Why not an unobstructed (schiefspiegler? Yolo? etc.) reflecting telescopes? 47. New design ideas? Sincerely, R.A."Dick" Buchroeder 8 S. Bella Vista Drive, Tucson, Arizona 85745 520 884 9800, FAX 520 623 3239; email rab@___rnet.com ===================================== Subject: The list. There has not been an overwhelming response to this list. I don't have a problem with that, it is only a couple of weeks old, and there are only a score of recipients, all of whom are busy. I have quite a few text files on binoculars, which I've been intending to share, so we won't run out of material, and we have had some input from others. However, there is a wealth of experience and knowledge among those who read this, and all list members would be very interested in other input. Dick's book outline contains many topics that could elicit heated debate in a smoke filled roomfull of binocular types, and there is no better audience or forum than this. We currently have 17 people on the list. I haven't sent a notice to any of the astronomy lists, or optics newsgroups, and am not in touch with birders. I'd certainly like to see more members, so let me know who might be interested, limiting 'nominations' to those with whom you'd like to spend a long evening in discussion of binocular instruments. --Peter ========================================== Subject: Resolution I was hoping for debate, and we've got it. In List #2, I said: "Binocular telescopes do not increase resolution over a monocular instrument, but greatly increase contrast & reduce fatigue over long observing sessions." I never argue with people who are better informed than I, but I'm going to do some more reading & expect to have a zinger of a reply to this post from my friend Bill: Date: Fri, 14 Nov 1997 19:28:45 -0500 (EST) From: Capt9999@___om While image brightness is not enhanced by having two obyjays, RESOLUTION is enhanced. This is due more to biology and neurology than mathematics. For more input, you could contact Dr. Dan Vokobratavich at the U of A's Optical Sciences Center. Regards, Bill Cook ======================================== ==================================== Binocular List #6, 11/25/97: Collimating tips, For Sale, History Lesson ===================================== Subject: Collimation From: Charles Orzech I just acquired a pair of 7X40 NVA's from Deutch Optik--very nice glass--sharp right out to the edges of the field! Can anyone give me some tips on collimating my 15X80 Yashimas? They are inclined and I have them "close." The trick seems to be getting the prisms exactly centered. Any suggestions? --Charlie Orzech ==================================== Subject: For Sale We inagurate the 'for sale' function of the newsletter with this issue. There are any number of potential problems with mail order of binoculars. Assuming the best intentions on all sides, the seller might not know of a missing or repaired part, or be certain of the identity of the instrument. Binoculars are very suseptible to shipping damage, since any shock or vibration can knock them out of collimation. A seller should make clear whether he can accept them for refund. The buyer must not assume that this standard of business practice will be adhered to by all businesses, or that individuals will be able to offer a guarantee. --Peter (The above does not pertain to the post below, but is a general caveat I will include on occasion) ====================================== Subject: For Sale From: DeutOptik@___om We've recently accumulated several big Japanese glasses that may be of interest to your readership. They are as follows: a) "Big Eyes" Ships Binocular, 20x120, made by Nikon, trunion mounted (with yoke and pedestal; lacks only the bottom mounting plate), fully reconditioned optics, nice "battleship gray" cosmetics, recovered from salvaged tuna boat, sealed and gassed for outdoor mounting, one pc. only, price $2500 b) WWII Japanese 20x120, with assorted kanji markings, in original wood box, complete but disassembled, unrestored but certainly a worthwhile project, as-is price $1500 or we will reassemble and recondition for $2200. c) WWII Japanese 15x4 degree (100mm), with assorted kanji, unusual size, good condition but could use a cleaning, as-is price $1200 or we clean for $1800. d) WWII Japanese 15x80 Battery Commander Scopes (aka trench periscopes or rabbit ears), assorted markings, bottom mounting apparatus, nice shape but require cleaning, if you clean $600 and if we clean $900 e) three (3) assorted Japanese 7x50, one is WWII, one marked "Made in Occupied Japan, one made by Micron (?), all are IF, porro prism, with leather cases, all have been cleaned and collimated, nice glasses for the money, all 3 for $250 "All items include a 10 day money back trial period, call before sending" --Mike Rifkin, Deutsche Optik ============================================= Subject: Various & Sundry From: DeutOptik@___om Other stuff your readers should know about: a) great source of optical parts for US military binos, plus enormous microscope expertise in sales and service: call I. Miller & Sons at 215-925-2285. b) Arthur Frank (well-known collector in UK) has a short but informative booklet on how to choose binoculars. I have a copy somewhere but can't find it at the moment. Still, if anyone knows him, he has great experience and expertise in the field. c) Fargo Ent., a Los Angeles-based outfit specializing in camera repair eqpt, is a good source for housing leather, greases and lubricants, etc. Call 707-446-1120, e-mail curt@___-ent.com Let me add that we are hosting an open house at our new facility on Friday, December 19 in the afternoon and early PM. All readers of the newsletter are welcome. Directions, discount hotel facilities, and some pretty good deals on oddball items we have laying around are the temptations. Come on down if you're so inclined. s/ Mike Rifkin, Deutsche Optik ============================================= Subject: The first known binocular (Excerpt from a talk to the Antique Telescope Society, 9/97) Binocular telescopes were conceived during the earliest days of the telescope. When spectacle maker Hans Lippershey developed his telescope, it became the earliest telescope whose documentation survived to the present day, and is considered the earliest known telescope, although probably not the first to be created. The record of his invention makes such a good story that one is tempted to think it became embellished over the years. When Lippershey applied for a patent on his instrument in 1608, the bureaucracy in charge, who had never before seen a telescope, asked him to build a binocular version of it, with quartz optics, which he is reported to have completed in December 1608. It was probably 3 or 4 power, and an inch and one half or less in aperture. Henry King quotes a government document, "On the petition of Hans Lippershey,...It was resolved, that some of the Assembly do form a committee, which shall...enquire of him whether it would not be possible to improve upon it, so as to enable one to look through with both eyes..." First a monocular and then a binocular telescope were tested. These instruments passed inspection, but the patent was denied because other telescopes were already known. Lippershey was asked to make two more binoculars, and all three were finished inside of five months. On request, he lowered his price for the three binoculars from 1000 florins to 900 florins, which might be about equal to 1000 dollars today, to the poor man of today. The binocular telescope is therefore as old as the monocular telescope, and in fact if this record is correct, 3 of the 4 earliest documented telescopes were binoculars. The immediate regression of the telescope into the popular monocular form is seen as an atavistic reversion by the advocates of the binocular, but to dwell on these losses is fruitless. --Peter ====================================== =================================== Binocular List #7: 12/18/97 ================================= From: DaveTrott@___om Thanks for putting me on your binocular list. I am very interested in several ways. I have built a pair of 30x60 binocs using Pentax 60mm refractor objectives and a surplus 10x50 binocular (minus objectives). I also had considerable contact with Robert Sudding who built a 20" (?) binocular telescope (a la Lee Cain) and a smaller 14". I had the opportunity to use these beauties a couple of times. I have recently experimented with my own 13.1" binocular telescope of highly modified design. I will contribute a brief explanation of my experimental results to this group as soon as I find the time to write it. I think the members will find it interesting and amusing! Dave Trott =========================================== Subject: Binocular Newtonian telescopes Those of you who do not frequent amateur astronomy meetings & have not viewed through a large binocular reflecting telescope, might wonder what the fuss is about. These telescopes, with two mirrors, each 6 to 20 inches in diameter, give unbelievable views of planets, nebulae, clusters, galaxies, and whatever else is out there. They are certainly grist for the mill of this list. They have much longer focal lengths than other binoculars, and are therefore much higher magnification, often 100 or 200 power. This means that the maker must engineer a very precise adjustment for collimation between the tubes, and successful instruments are the products of skilled craftsmen. There is a collection of images of binocular telescopes made by amateurs, including a couple that look to have 15 or 18 inch mirrors. There are no captions to identify makers, I believe the author is in Europe but travels to the U.S. -- Peter http://automation.valmet.com/kyyroju/bindob1.htm ================================= Subject: Nikon 10 x 42 If a binocular aficianado were to be forced to identify a glass, in current production, that gave the best optical performance, that binocular might be the Nikon 10 x 42 E. (I just checked the spelling on that fourth word. I never knew an aficianada was a female aficianado. We need some of them in the binocular club.) Nikon makes no claim for weather resistance for the 10 x 42s, but I was still surprised to read this post to an astronomy list: “Re: Nikon 10x42 SE CF Binoculars..... these things are NOT well sealed. There are two small holes on the top of the plastic fitting that holds the ocular in place. These holes allow moisture to go from the outside directly to the interior of the lens assembly. I think this is a very poor design and was shocked when I discovered this the hard way.“ Does anyone have one of these to check this out? It’s hard to guess exactly where this hole is found. ==================================== Subject: History, continued Galileo’s instruments were probably of considerably better quality than their predecessors, and his surviving lenses have been tested with very good results. Many references on Galileo describe a binocular telescope of his design, but some recent Galieo studies disagree concerning his construction of this binocular. Giovanbattista de Nelli, in his 18th century collections of Galileo’s letters and other works, wrote that in 1618 Galileo constructed a helmet with a frame containing two small telescopes, to be used on board a ship, and named it the celatone. There are many references to the helmet in Galileo’s writings, including construction, testing, presentation to sponsors and ambassadors, and the development of a gimbaled observer’s chair to counteract the motion of the ship. Instrument historian Silvio Bedini summarizes the known documentation and accepts the notion that the helmet was binocular. However, telescope historian Albert van Helden notes an1881 Italian history of “Cannocchiali Binoculari”, by Antonio Favoro, in which it is claimed that the helmet had a single telescope. Van Helden believes that Galileo did not use a binocular instrument, and the idea should be regarded as less than certain, pending further research. Ottavio Pisani, an Italian amateur astronomer, wrote to Galileo in September of 1613, discussing a binocular telescope, but his other letters to Galileo and his publications do not mention it. Daniele Chorez made optical instruments in Paris, and is thought to have made a binocular telescope by 1625. A notice publicizing and depicting his microscopes and telescopes shows the binocular. The left telescope is attached to a frame, and the interocular adjustment is accomplished with the right tube. A screw was attached to the frame to use for supporting the binoculars on a fixed object. The notice was found in 1880 by Gilberto Govi, who wrote an article with the most intriguing title, “Nuovo Documento Relativo alla Invenzione dei Cannocchiali Binocoli”. (Cannocchiali, or cannon, being the contemporary Italian term for these very earliest telescopes). ================================ =================================== Binocular List #8, 1/9/98: Repair, Alignment ================================================= Subject: Repair We have 5 opticalmen on the list. (Is it ex-opticalmen, or once an OM, always an OM?) Many collectors are familiar with repair facilities. I’d like to compile a list of resources for the repair of old binoculars, mainly repairmen but also sources of materials. Readers who can contribute to this should mail me with names & addresses, and background or special skills of the repairman. There is much to say on this topic, and I am writing up notes on pitfalls & hazards of repair, the early German zinc alloy bodies that disintegrate from within, preserving old lens coatings, etc. --Peter ================================================= Subject: Repair of circa 1900 Zeiss Dosenfernrohr From: Larry Gubas Lngubas@___om I have found an old Zeiss piece in pretty bad shape, a Dosenfernrohr (literally, a tin can telescope). It is the original revolving eyepiece telescope made between 1895-1905. It needs a cleaning of the original prism and a new (rather a "new old") eyepiece on one of the revolvers. This is a special and an especially difficult piece for me to consider to send to someone. These are primitive (if I could consider any Zeiss work to be primitive) in construction and would need someone to replace an eyepiece and clean the prisms. These items are rare and the Zeiss serial number is #115. I am asking since I have never trusted such a piece for repair before. I do not think that this will be difficult work to do in terms of repair but rather since it is a bit fragile and a previous owner did some pretty stupid things to it. I know that I am asking for a lot in seeking another eyepiece for the Dosenfernrohr but I have hopes that someone out there has an old eyepiece that could be adapted. That is why a collector/repairman would be preferable. Maybe we could challenge the group to make a recommendation. Cleaning should not be a problem since it is rather simply made and put together although you may be right about the zinc materials. [Old binocular bodies of unstable zinc alloy.] I am told that the old eyepiece was taken off to create a tripod mechanism and was discarded. --Larry ============================================= Subject: Internal alignment of oculars From: "Loren A. Busch" We [Captain's Seattle] have been playing with the new Vixen bino from Orion, the one with the interchangeble eyepieces. [80mm, 45 degree offset oculars, $879.] One unique thing about them, the eyepieces are marked to assure that they are inserted rotated to the correct position to maintain collimation. There are also instructions that come with the binos for properly aligning other eyepieces if the owner choses to use them. Our experiments are consistent with my previous experience, and the experience of Sid Knight in trying to find matching eyepieces for either binocular viewing adapters or bino telescopes. It is just as big a problem with TeleVue as with Celestron plossls, Celestron Ultimas, and Orion Sirius plossls. It comes from the factory with 25mm Kellners that give 36x. We have tried all the way down to 10mm eyepieces and found problems getting the eyepieces to align. I suppose that with an infinite numer of 'identical' eyepieces we could find two that match, but even as good as our stock is, we had trouble finding matching eyepieces. Color is acceptable with 10mm eyepieces, at least in daylight. Even with the 25mm issue eypieces you can see the exit pupil move as you rotate the eyepiece. I would suspect that you can see this in most scopes with a lot of eyepieces. This is very visible without a collimator. The Vixen binos appear to be using the objectives out of the Premium 80mm. The specs say they are 900 mm FL which matches the specs on the Premium 80. There is a little more color at high magnification (80x) than the Premium 80, I attribute this to the additional optics (prisms) in the path. Sid Knight is an active member of SAS who has made several binocular viewing adapters using binocular microscope heads and was the first to point out and demonstrate the problem of non-concentric eyepieces to me. He also pointed out the problem in most binocular viewing heads that he saw as a polarization effect but I speculated (later confirmed) is really a phase shift problem caused by the beam splitter. He noticed this in a binocular viewer marketed (formerly) by Celestron and talked to someone at Celestron about it. With a chuckle he was told that he was only the second person in years of marketing the binocular viewer that had noticed the effect. I talked to Bill Cook about it at the time to confirm my guess that it was a phase shift problem and he referred me to the article (not yet published at that time) from Zeiss on phase shift coatings in roof prism systems. Busch There are very few binoculars on the market that have interchangeable oculars. It is a great idea that is difficult to achieve with high standards. Binoculars are highly corrected systems, and the oculars of quality instruments are designed to correct the aberrations of the short focus objectives, problems that are often enhanced by the prisms. Vixen has a 60mm ‘Pastoral’ model and the 80mm discussed above, that use standard 1.25 inch telescope eyepieces. The Pastoral shows more color around objects than most 60mm binoculars. Swapping oculars is an art that has been developed by Kevin Kuhne, who has taken early Japanese binoculars and replaced the oculars with German wide field eyepieces. He has measured the optical qualities of these oculars and matches the ocular to the objective. --Peter =============================================== Subject: Binocular Vision From: "Loren A. Busch" I'm interested in any references that might be available on the difference in visual perception, monocular (typical telescope) vs. binocular. There is a lot of anecdotal info that 'you see more with both eyes' (including yours truely) but I wonder what might have been published on the subject. Busch I have some material, and will look for it as I search for facts to buttress my rebuttal of Bill Cook’s contention that resolution is better with binocular vision than monocular vision. I have received a message from list member Bill Beacom that Cook is right, so I’m ready to concede if absolutely necessary. --Peter ================================================== Subject: Message from the antipodes. From: Fred Watson I thought I might just send a quick e-mail to wish you and all recipients of the Binocular List very best wishes for Christmas and the New Year. Though you haven't heard anything from me yet, I do read each issue with much pleasure. I think you already know that the two largish monoculars for which I'm responsible (the Anglo-Australian Telescope and the UK Schmidt Telescope) keep me very busy! But one of these days I'll manage a contribution. Keep up the good work---it's much appreciated. All best wishes, Fred (Fred’s modest armada of instruments can be seen at http://www.aao.gov.au/local/www/ras/instruments.html Here is how he described his work to me: My main creation in the AAO's instrument suite was FLAIR, a multi-fibre system for the UK Schmidt Telescope, but I've also worked on other multi-fibre spectroscopy systems. From the web page: Fibre-Linked Array-Image Reformatter (FLAIR) FLAIR is a multiobject feed for the FISCH spectrograph at the UKST. Up to 91 objects can be observed simultaneously, covering 40 square degrees of the sky. Fibres are cemented to negative copies of Schmidt plates using a semi-automated FLAIR fibre positioning system (AutoFred). This is to introduce a field-rotation to compensate for the gross effects of atmospheric refraction over the telescope's wide field. ================================================== Subject: The List We have some really stellar participants on the list. You can tell because they don’t say anything. This list is quite small because it hasn’t been publicized, if it were announced on the astronomy lists it would grow considerably. For now, we’ll keep it small, but I’m open to ideas about getting some more members. Here is the current line-up: Peter Abrahams telscope@___a.com Writer on the history of binoculars, telescopes, and microscopes. Bob Ariail skyhawk@___net Co-author, Alvan Clark & Sons: Artists in Optics. Leading private collector of telescopes in the U.S. Bill Beacom bbeacom@___t.net Binocular collector. A source for parts. John Briggs jwb@___yerkes.uchicago.edu Engineer at Yerkes Observatory, now on assignment at Apache Point, N.M., at the Sloan Digital Sky Survey. Telescope historian. Dick Buchroeder rab@___rnet.com Lens designer. Loren Busch LBusch@___tcom.com Captain’s Nautical, Seattle Paul Cerra pc@___bly.net Navy opticalman, Swift Instruments Bill Cook Capt9999@___om Navy opticalman, Captain’s Nautical, Seattle. Frank Doherty Dohertyfe@___om Collector, Kriegsmarine instruments in particular Jack Eastman Jack.F.Eastman@___com Optical engineer. John Gruver gruver@___.com Binocular retailer. Larry Gubas Lngubas@___om Archivist & editor of Zeiss Historica. Jack Kelly BINOCS@___om Collector Ken Launie LAUNIEK@___y.polaroid.com Collector & historian of telescopes, mechanical engineer. Bill McCotter bjmac@___ortco.com Collector Charles Orzech ORZECHC@___t.uncg.edu Binocular user & collector, translator of Japanese. Earl Osborn osbear@___et.com Optical instrument repairman. Randy Pakan Randy.Pakan@___rta.ca Collector, telescope maker, professional in stereo mapping.. Mike Rifkin deutoptik@___om Owner of Deutsche Optik. Steve Rohan binoptics@___link.net Collector, author of “Eyes of the Wehrmacht”, study of German 10 x 80s. Steve Stayton milstay@___rnet.com Opto-mechanical engineer, collector of binoculars & other optics. Cory Suddarth corys@___tel.com Navy opticalman, telescope & binocular repairman at Telescope & Binocular Center. Dave Trott DaveTrott@___om Amateur astronomer & telescope maker Fred Watson fgw@___n.aao.gov.au Author of “Binoculars, Opera Glasses, and Field Glasses”, professional astronomer. ============================================= ===================================== Binocular List #9: 2/3/98. Collimation. ================================ Subject: Mechanics of adjusting & securing collimation. This is the beginning of a list of methods used to adjust & secure alignment of binoculars. Input is solicited. --Objective mounted in an eccentric cell. There must be a disadvantage to this one, otherwise everyone would be using it. It makes the binocular more bulky at the objective. But the advantages are many: It is very secure, the prisms are firmly seated in a tight shelf. It can be adjusted without disassembly. --Prisms slide laterally in a milled recess. Occasionally, this adjustment is done from the outside, with ‘push-pull’ screws. --Prisms tip, along their long edge, one edge remaining in the seat, and one edge hovering above the seat. The prism can be supported from its side, by shims, or other means. This seems a precarious & less precise method, but it is commonly used. --there are many others. ============================================= Subject: Standards for Collimation A few references to standards for binocular collimation. ==== Brown, Earle. Optical Instruments. Brooklyn: Chemical Pub., 1945. Brown was at the Santa Anita Ordnance School at the time. On p421, he states that generally accepted tolerances are: (He expresses them in terms of the optical axes of binocular at the ocular, not in terms of the viewer’s eyes). Vertical: should be parallel within 3 minutes. Horizontal: convergence not over 1/2 minute & divergence not over 3 minutes. On p274, he switches to the more commonly used convention that humans can tolerate 3 minutes of convergence but only 1/2 minute of divergence by the eyes. On page 423: image tilt relative to the opposite image, occurs in Porro I binoculars, with a pair of prisms in each side that can rotate relative to each other, which causes the image to rotate. Brown notes that for optical measuring instruments, tolerances are 1 to 2 minutes, but does not mention hand held binoculars. ===== Bureau of Naval Personnel. Opticalman 3 & 2. 1966. (Reprinted as Basic Optics & Optical Instruments, Dover, 1969.) The US Navy’s standards are: Vertical alignment, 2 minutes “step” (a horizontal line can have a misalignment measuring two minutes of arc.) Horizontal, for the instrument’s optical axes, 4 minutes of divergence, 2 minutes of convergence. Image tilt, one degree (viewing a distant vertical line, the two images can be misaligned by one degree). These last two specs are far looser than I would expect. ===== Home, R. Binocular Summation and its Implications in the Collimation of Binocular Instruments. SPIE vol. 98, 1976, pp72-78. This is a very interesting & complicated paper. Binoculars collimated with parallel axes do not allow the vergence mechanism of the eyes to match the accomodative state. The normal relaxed accomodation of 1 dioptre cannot be accompanied by its preferred convergence. This paper shows that the effect of this is a measurable decrease in binocular summation, which results in a decrease in contrast detection. Home believes that collimation standards for binoculars could be relaxed if they were modified to work with the accomodative vergence of the eyes. ===== Ostrovskaya, M.A. et. al. Allowable Deviations From Parallelism for the Optical Axes of Binoculars. Soviet Journal of Optical Technology, 45 (10), Oct. 1978, pp613-616. The author states: “The tolerance values encountered in the literature amount to 2 to 40 arc minutes in the vertical plane, 4 to 60 and 6 to 180 arc minutes in the horizontal plane in the case of converging and diverging axes, respectively. Soviet optomechanical standards are 15 arc minutes of vertical divergence, 20 arc minutes of convergence by the axes, and 60 arc minutes of divergence. One degree of convergence by the eyes (=60 arc min. of divergence by the axes of the instrument) would be easy to tolerate, but the other specs are difficult to understand. Some Russian binoculars are quite good, far exceeding these standards. A series of tests are described, subjecting various victims to misaligned binoculars for 15 to 60 minutes (of time). They find that people can tolerate binoculars with 30 minutes vertical misalignment, 40 minutes convergence, and 100 minutes divergence. I believe an experienced or critical viewer would not keep a binocular with these errors. They note that deviation from parallel is defined by a=b(c-1), a is the angle of deviation, b is the angle between the optical axes, and c is the angular magnification of the system. I guess this means that a non magnifying system cannot have deviating axes, which seems wrong. However, freeviewing slightly divergent photo pairs involves diverging the eyes much more than these standards. It is the magnification that requires binoculars to be of such high standards. Even a low magnification, 6 power binocular gives an optical deviation equal to 5 times mechanical deviation. They discuss the time factor. 60 minutes was chosen for the outside limit because after one hour of viewing through an aligned binocular, fatigue was noticable. My experience is that a high quality instrument can be used for much longer than this. Dizzyness, nausea, and related effects increased with time, or rather the maximum deviation tolerated decreased with time, but only to 30 minutes. Increasing to 60 minutes did not increase effects. This part of the test did not seem rigorous. My experience is that there are counter-effects: headaches increase, but one can also ‘get used’ to misaligned images. Some of the tests required the subjects to keep their eyes in motion across the field, an interesting variation. --Peter ============================================ Subject: More history. Anton Maria Schyrle, from Rheita, Bohemia, published a very influential book on optics in 1645, ‘Oculus Enoch et Eliae sive radius sidero-mysticus’. This volume contained a twenty page section on binocular telescopes, which was the single greatest influence on other makers of these instruments in the century to come. Francois Lassere, the Capuchin Pere Cherubin d’Orleans, developed the binocular telescope in a characteristic form, separating the tubes with a metal frame and placing this in cardboard boxes that extend by sliding the smaller box from within the larger. Cherubin made about 30 of these in the 1660s and 1670s,and there are a few of them in European museums. In 1671, he published his ‘La Diotrique oculaire’, which described both binocular microscopes and telescopes. His second book, ‘La vision parfaite’, of 1677, showed several of his designs for hand held binoculars, as well as binocular telescopes and instruments by Cherubin and de Rheita. Johannes Zahn, ‘Oculus Artificialis Teledioptricum sive Telescopium’, was published in Nuremberg in 1685. This volume showed illustrations of binocular telescopes that were long twin tubes mounted in 2 large discs, in front & back. String between the tubes can be pulled taut to approximate collimation, a clever and somewhat effective method of alignment. J.M. Dobler made optical instruments in Berlin circa 1700, and two of his binocular telescopes are in Moscow’s State Historical Museum. One is a cardboard oval tube, parchment covered, 88 cm long, with objectives and oculars in wooden lens cells. The other is a 75 cm cardboard rectangle, leather covered, with wood lens cells and leather lens caps, with the inscription “Binoculum oder doppeltes feld perspectiv”. Pietro Patroni was a mid 18th century maker of microscopes and telescopes in Milan, Italy. His binocular telescopes closely follow those illustrated in La vision parfaite by Cherubin d’Orleans,. Both makers decorated their instruments with elaborate gilt tooled leather, presumably because many of their customers were noblemen who were purchasing collector’s items or conversation pieces. A binocular telescope made by Patroni in 1714 is in the Deutsches Museum in Munich. The silver ocular covers swing open to reduce glare. The objectives have about 12 mm of clear aperture, with about 10 times magnification, and the three lens erecting system has no aperture stop. Another dated 1719 is in the Pierre Marly collection in Paris. This is 30 cm in length, covered with fishskin and vellum, and the key is used to adjust focus. The Museo di Storia della Scienza in Florence possesses a Patroni binocular from the 1670s. Interocular adjustment is accomplished with adjusting screws that give four settings for eye spacing. His instruments were highly regarded in his time, and contemporary British instrument salesmen suggested their telescopes could compare with “those of the celebrated Pietro Patrone at Milan”. Milan had another maker of binocular telescopes around 1750. Francois Baillou made both monocular and binocular forms of microscopes, telescopes, and opera glasses. He made deep green telescope lenses for solar observation, and seems to have used a star diagonal he called his ‘reflection system’, though it is unclear if it was a prism or mirror. His binocular telescopes are shown on his trade card and his pamphlets. Milan seems to have fostered a creative and productive optical industry in the 18th century, it has been the subject of articles by ATS member Alberto Lualdi of the Universita di Pavia, appearing in the Bulletin of the Scientific Instrument Society. Lorenzo Selva was part of a family of instrument makers in Venice through the 1700s. In his ‘Dialoghi Ottici Teorico-Pratici’ (1787), many instruments are described and depicted, including telescopes and binoculars. --Peter ======================================== ========================================= Binocular List #10: 2/10/98. More designs for collimation, Image stabilizing prisms ====================================== Subject: Additional methods of collimation: From: "Jack Kelly" --adjustment of the hinge center bushing using eccentric bushings - example Avimo 7x42 --adjustment of the bodies by moving the hinge mounting points - example early Zeiss ======== Some WWII USN binoculars maintained collimation by securing the prism with a wire. These included the B&L Mark I 7x35, and B&L Mark II Mod 0 7x50. This is reported to be a very secure fixation. Can anyone explain how this worked? And a question from the same era: The B&L Mark 18 7x35, and B&L Mark 24 8x56, are noted to have ‘leached optics’. What is a ‘leached optic’? --Peter ======== In the Goerz D.F. 03 (fig. 48 of Seeger, ‘Military Binoculars’), collimation is accomplished by moving the prisms. The screws into the housing cover are removed, and a thin screwdriver inserted into the holes to turn the prism adjusting screws. The cover doesn’t have to be removed. Turning the screws causes the prism to move, working over small pressure blocks. This method of collimation is known as the Goerz adjustment or ‘little pressure block’ adjustment and was also used by Goerz in other models. Patented by Goerz on November 29, 1907 (German Patent No. 201 653) Collimation using an eccentric cell for the objective was developed during the first decade of the 20th century, according to Seeger, Military Binoculars. I haven’t yet found a specific example in the book of such an early model. What are the earliest examples any reader knows of, using this collimation method? Peter ============== Eccentric rings are not being used much now, not because of bulky objectives as much as it is much too expensive to produce them. They are the best (not the easiest ) way of aligning binoculars as it does not introduce lean or tilt which causes swing. --Paul Cerra ==================================== Subject: Image Stabilizing Prism Canon has recently been marketing vibration compensating binoculars with "vari- angle" prisms. Does anyone know how they work and how they manage to avoid collimation problems? --Charlie Orzech There are two image stabilizing binoculars on the market that I know of. One is a Zeiss, where the prisms as a unit are mounted in a pivoting housing that is partially isolated from the binocular body. It is free to move, similar to a gimballed compass on a ship. Both sides work as a unit, so collimation is not a problem They are reported to work very well. The Canon system inserts into the optical path a wedge prism that can change the angle of deflection of the light beam in response to movement. The prism is similar to two small panes of glass, separated into a wedge, surrounded on the edge by a membrane, and filled with a liquid. Tiny motors push the corners to change the angle of the wedge. The motors work in response to movement of the binocular. I am not sure how collimation is maintained, but presumably the motors on each side are linked so they move identically. They also are reported to be quite successful. Finally, how did any earlier attempts work? There have been gyroscopic attachments that fit into camera tripod sockets, and presumably they could fit in a binocular socket. --Peter ======================================= ========================================================== Binocular List #11, 2/10/98: Stabilizing Prisms, Offset Wedge, Removed German Markings, & more replies ======================================================== Subject: Offset Wedge Attachment The 'Binocular Offset Wedge Attachment, Mark 7' was made by Polaroid for WWII 7 x 50s. It is two short metal cylinders that fit over the objectives and are held by a clip. In each cylinder is a clear plastic wedge with seven holes drilled through it (along the optic axis), covered by a thin plastic window. The thick plastic is about 7 mm thick on the right edge and 15 mm thick on the left edge. It has the effect of laterally offsetting the field of view, retaining a faint image of objects directly in front (the faint image is from the holes drilled through the wedge). Some were labeled for attachment to Mark 13 binoculars. A 'Schedule of Binoculars' from 1944 has it listed with the Mark 22, and the Mark 27 has a note, 'wedge attachment omitted' (as if it was issued with the Mark 22). These are all B & L 7 x 50s. --Peter I received a letter about the use of this device from Earl Osborn: Return-Path: I also have a couple of these, including a variant that is a stand-alone unit with a handle. I did a little research a while back as well. According to one of my sources, who also has one and researched it, it is used in conjunction with naval gunfire training. Here is the concept; the weapons officer gives a set of coordinates(as determined through the bino with the offset wedge assy.) of an actual target to the mount captain. The idea of the offset wedge assy., is to offset the angle without affecting the range. In this manner the target is not actually distroyed, but the rounds will appear to be on target. Earl ============================================================== Subject: Message from Hans Seeger. A letter from Hans Seeger asked about the wedge assembly, and included this note: “Could you please give per e-mail my name and address to your friends? If needed (and if I know the answer) I can answer special questions in form of conventional mail. If someone wants my new book on ‘Optical Equipment’ with a dedication, he should contact me” Hans Seeger, Mainzer Strasse 25, D-65185, Wiesbaden, Germany. Tel/Fax: 0611-37-97- 82. The book is ‘German Military Technology: The Optical Equipment’, a large & thick paperback of reprints of Zeiss specification sheets on their military equipment 1930-1940. Only about 20 pages cover binoculars, but many other interesting instruments are shown. It is about $100. ======================================================= Subject: Eccentric rings, Lens coatings From: "Eastman, Jack F" Eccentric Rings -or- how not to live to a ripe old age. My first exposure to observational astronomy was a view of the moon through my dad's Zeiss 8X30 binos, when we lived in Denver and I was in the 2nd grade. The hook was firmly set by a view of Jupiter at Knotts Berry Farm, shortly after our move to (choke) Calif. in about 1949. One thing led to another with the help of the Griffith Observatory etc. and ultimately I got the use of the 8X30's Eventually I graduated to a real telescope (Polarex (Uintron) 40mm alt-az) and then to a Polarex 60mm. I found that I could remove the eyepiece from the 8x30 and use it in the 60mm. It gave a beautiful wide field at about 56X. So far so good, but my curiosity got the best of me and I took one of the objectives out of this bino and examined the workings of this instrument. I replaced the obj. and much to my horror the thing had terminal double vision! Oh no. My dad will certainly notice this and I'll die a slow horrible death. Well I discovered the eccentric ring business and with a fair amount of fiddling managed to get things back to collimation. The Binos are labeled Carl Zeiss Jena, in a logo that looks like a lens, on the right side and Deltrintem 8X30 on the left. I think my Dad got them some time during WW2 when he was in the service. Lots of aluminum or magnesium alloy, the body and eyepiece barrel, with brass "cells" over the infamous eccentric ring business on the objectives. The optics are uncoated. I am amazed at the first impression of even a really cheap bino, in that one has the immediate impression of a sharp contrasty image before one becomes aware of the small field, coma etc. I believe this is due to the significant improvement in throughput and contrast of coated optics. The aforementioned Zeiss has 12 glass- air surfaces, and at a nominal 5% loss per each, the throughput of the whole thing is 54% (coated, even simple MgF2 would increase this to 89% (assume 1% loss/surface) All that light that isn't getting through is going somewhere and that is causing a loss of contrast. The coated optics of even the cheapies give the illusion of superior performance in this respect.. The business of stray light is a real bucket of snakes. I too have heard that multi-coatings scatter more, and it stands to reason. The more stuff on a surface the rougher (even at angstrom scales) it becomes, hence, more scatter. The reflectance losses, however are materially reduced. So which is worse?? high specular reflections (ghosts) or more scatter of less light. I personally believe that each case must be measured and evaluated. Having been involved in both the measurement and analysis of stray light I will say it is far from a simple problem. Some ideas may be gleaned from: Optical Scatter: Measurement and interpretation, John Stover, from SPIE 23rd annual international technical Symposium on Optical & Optoelectronic Applied Science & Engineering San Diego 15 Aug. 1988 Applied Optics and Optical Engineering vol VII, Chap.7 Elson Bennett & Bennett. Intro. to Surface roughness and Scattering Jean M. Bennett & Lars Mattsson, Optical Soc. of America. These references are like trying to drink from a firehose, but could be useful if one really wants the gory details. The other close encounter of the worst kind with eccentric rings involves a 35mm f/2.8 Zeiss Flekogon lens. I noticed some stuff between the elements in the vicinity of the iris. How hard can it be to remove the front or rear group and clean it up? The answer, not hard at all, but we must get it back together! That could be another story. Why were there so many rings on the back of this thing? I removed the largest, thinking it would let me into the part of the lens that needed cleaning. It did, but then I discovered the %$#@___ntric ring business. Shades of the bino experience of 45 years ago. This lens is designed so the rear group can be moved laterally with respect to the front! I was able to align this thing by examining the axial image of a "star" and tweaking until all evidence of coma was gone. The lens performs much better now, it probably needed this alignment which wouldn't have happened if I had marked everything and put it back the same way. Removal of the goo between the elements was probably the real reason the lens works better! If good optomechanical design dictates 8 parts, the Japanese will do it with 3, and the Germans (Zeiss in particular) will use 67. FJE ============================================================= Subject: Image Stabilizing Binoculars There have been some posts to various newsgroups on binoculars with mechanisms to stabilize the image against movement. It isn’t right to reprint someone’s words without permission, so I edited the texts into one essay. Like everything on line (or off line), it cannot be accepted as entirely accurate. ==== The Canon stabilized work very well, but the batteries need to be changed after only 10 minutes of active use. In the 15 X 45's and 12 X 36's, the image stabilization works quite well, but neither binocular impressed me with image quality or light throughput. The Peleng 12x40 stablized binoculars take eight AA cells but they last a very long time, perhaps 20 hours. They use a mechanical gyro to stablize the suspended prisms. The gyro is noisy, but stabilization works extremly well. It takes over 2 minutes to spin down. It will even work on 6v (rather than the 12v). They just about double the detail I can seen on the moon. Splitting Albireo is easy, and Messier objects are visible. Zeiss, Zenit, Fujinon and Frase-volpe also make stabilized binos. ==== Here is an article from the web site: http://www.psych.helsinki.fi/archives/eos/1996.5/1510.html Willem-Jan Markerink (w.j.markerink@___) Sat 29 Jun 1996 19:59:31 +0000 Today I had the rare chance of testing all three types of IS as currently used in binoculars; the mechanical (cardanic system) Zeiss 20x60 S, the electronical (gyro sensors/actuators) Canon 12x36 IS, and my electro-mechanical (electro gyroscope) Russky 12x40. As reference we used a state of the art Leica 10x42. The shop owner had warned me that in a previous sample test, someone from a Dutch birdwatch association had claimed that the Canon suffered from chromatic abberations. When looking at white letters on a black background, we could now both confirm that. It's not much, you have to know what to look for, but it's also certainly not on par with Zeiss or Leica. But neither is the price....;-)) Further optical-only (not IS related) considerations: my Russky had a slight yellow shift compared to the other binoculars. But he said all Russky mono- and binoculars suffered from that. Most important aspect of course was the performance of the IS systems. I could confirm my early opinion that the Zeiss IS was rather nervous; stabilized, but not slow in transferring hand movement to image vibrations. The Canon was a whole lot better, but comparing a 20x with a 12x magnification is rather dishonest. Surprisingly, to both me and the shop owner: the Russky binoculars had the best damping effect of all. Also 12x, but an even slower movement of image, like watching a film at very slow speed. The damping of large angular vibrations was also better. However, the bulkyness of my Russian contraption (1.5kg), together with the requirement to focus each eyepiece individually and a huge power consumption (6xAA, 12V or 24V), makes it rather impractical, but nevertheless fun to use. ============================================================ Subject: German military glass with removed engravings From: "Martin, Dick" Does anyone know why do so many of the German binoculars from WWII era have defaced eagle and swastikas? I suspect that defacing these was a requirement set by Allied Governments to allow individual pieces to be brought back as war prizes. If so, did all governments require this? How did so many escape this defacement? I have spent many hours under a microscope restoring several of these to original (or near original) condition while muttering expletives throughout the process. There are some glasses I will not touch. I need enough of the image visible to get proportions. If the top prism cap is aluminum and if some of the eagle is visible I will engrave the entire image through the gouges. I will then begin resurfacing but stopping as necessary to re-engrave a portion of the image that is starting to dissappear. When I'm down to the point where there are only a few deep gouges left I will prime thickly then sand to bare metal leaving the primer in the deep spots. I will re-engrave the pattern into the primer which covers the deep spots and lift the paint out of the lines I previously have engraved in the aluminum. Its then a matter of finishing without applying to much paint then applying and wiping off the lettering paint. This is a trial and error process which doesn't work very well with flat paint. --Dick Martin ====== I've been told by WWII vets that when they brought back optics, they weren't at all sure that they would get past the 'inspectors' (whatever they called them). If there was any military approval or oversight on this, I haven't heard of it. I have seen ads in English & American magazines, Edmund surplus etc., so there was some larger scale 'importation'. My guess has been that after a long war, these vets didn't want to look at any more swastikas; and even if they did, their wives wouldn't want them in the house. --Peter ================================================= =============================================== Binocular List #12, March 1, 1998. Great Western, Stabilized Prisms, Zeiss Teleater ==================================== Subject: Meeting in Los Angeles, April 30 The Great Western Show will be the first weekend of May. Thurs. April 30 at noon is a ‘pre-admission’ entry. The Great Western is the largest gun show on the West Coast. There are some good optics to be found, but competition is significant. The informal gatherings that Steve has held on these occasions are the real reason to consider a trip to L.A. There is an important collection to examine, but also the very rare opportunity to confer with a dozen or so people who know something about historical binoculars & related subjects. --Peter From: Stephen Rohan I usually invite people over on the Thursday evening before the show which would be April 30. I dont know how many people will get your message, but I expect it will not be huge numbers. As you probably remember my "barn loft" is not big enough for a large crowd. I expect it could comfortably hold 15 or so people. Steve ==================================== Subject: Canon Image Stabilization 12x36 binoculars From: RAB I recently purchased a used pair of Canon 12x36IS binoculars through Astromart. They were approximately l year old, and showed absolutely no signs of optical or mechanical wear. The advertised lifetime with alkaline batteries is 1.5 hours; I've played with them for several weeks and have probably run them for an hour's accumulated use and they are still working fine. Canon says that the lifetime with lithium batteries is 7 hours. Since the stabilization is activated by pressing a stiff button, one doesn't tend to run the stabilization for long periods. The advantage of this binocular is that it doesn't rely on a gravity vector, and is not 'confused' by erratic motions. I used it very successful freestanding on an tourist car on a train rumbling over badly-maintained rail, and it does a fabulous job of smoothing out all but the meanest bumps. I also used it, sitting in the passenger side of a moving sedan, to read license plates of cars...effective for that too! However, the stabilizing technique uses a variable angle, liquid-filled prism in the converging beam of the objective lens. As such, when it is in the act of stabilization, the image shows both substantial lateral color and comatic aberration. Thus, when a tripod can be used, it should be used....that results in extremely fine image correction over the field of view. The eyerelief is pathetically short; they advertise 15mm and claim that to be "Long eyerelief", which of course is nonsense. I use mine by affixing spectacle lenslets to the rubber eyeguards, rolled down. At that, there is negligible eyerelief, but I can indeed then see the entire field of view (about 67-degrees apparent) and it is excellent. My pair is 'perfectly' collimated when used in the caged mode, but has vertical decollimation when in the stabilizing mode. I wrote to Canon to ask what it would cost to get this fixed, and they didn't give me a price...just told me to mail them in. Since they are out of warranty (I assume; they are a year old now), I haven't mailed them in...I can, with some strain, live with the decollimation. What causes it is a mystery. I subsequently viewed, at a local Tucson camera store, the 15x45, a 10x30, and another 12x36. The 12x36 and 15x45 behave the same as my 12x36, but the 10x30 appears to be somewhat different in behavior. The 12x36 essentially weighs 2 pounds, with battery and strap, and that's heavy enough to induce tremors...so in essence, the weight produces the problems the IS is designed to correct. Overall, though, the stabilization is excellent. I have a nephew who has cerebral palsy with almost incessant hand tremors, and he was able to successfully use the IS binoculars; however the weight is a problem even if the image is stable. I hand-held the 12x36 as Venus reappeared in the Eastern morning sky, and was easily able to see the crescent phase! It is also astonishing to hand-hold the glasses while viewing starfields; but coma is observable due to the stabilizing variable prism. Still, the reduction in tremor outweighs the image softening, and I assume that with practice I'd improve the image. Coatings are excellent, no apparent ghosts; however, there are 'image leaks' in the prisms that basically cause no trouble provided you have your eyes in just the right location. The technology is outstanding, but there is still room for improvement in the Canon binocular implementation. These are probably best suited to law enforcement and military application, not to amateur astronomy. They should be useful to birdwatchers if using a tripod or monopod is impractical. R.A.Buchroeder. ================================ Subject: Zeiss Teleater From: "Jack Kelly" Hello Experts, I am planning to submit an article to Zeiss Historica on the Zeiss Teleater 3X13.5 miniature prism binocular. The theme of this article would be the Teleater and its influence on miniature binoculars. This glass is characterized by close set objectives (inside the oculars), center focusing accomplished by moving the objectives and a unique shape common to all of the variations and copies. To the best of my knowledge, Zeiss was the first to market with this design. Does anyone have any information to the contrary? The first half of the equation is a listing of first the various Zeiss variations of this glass. My list of Zeiss Teleater variations include: The earliest version had no diopter adjustment. This came in basic black and at least a gold with brown lizard variation. My example is lizard and gold and has S/N 184044 which dates it about 1910. By 1912 the Zeiss catalog offered diopter adjustment. I know of at least three variations of this model. They include basic black, gold with brown lizard, and gold with mother of pearl. The mother of pearl and lizard variations were offered with detachable handles. Anyone aware of others? The second side of the issue is an attempt to put together a list of look alikes. My collection currently includes the following: Bausch & Lomb Prism Opera 3X15 Busch Thaliar 3X13 -not identical to Teleater but very close Goerz Fago Trieder Binocle 3 1/3X15 Leitz Binar 3X13.5 Oigee Oigelet 3X13 Unknown Prisma Binocle 3X14 I am also aware of a few others: Huet 3X13 Ross New Prism Opera Glass 3X13 Ross Vest Pocket 6X15 In addition, Zeiss made a Teleater lookalike called the Teletur. This was identical in all ways except for 6X magnification. Leitz made a similar Bidal in 6x15. If anyone has additional information, catalog pages or photographs and is willing to share please contact me. Many thanks, Jack Kelly binocs@___om ====================================== Subject: Heesch Optical This past week, I acquired a pair of binocs which look and feel exactly like the pre WW II B&L EE series. They are 6X30, brown leather covered, marked "Military Stereo" and have brass prism covers. They are in almost new condition and are marked, "Heesch Optical Co., Rochester, NY". Does anyone have any information about this company? --Jack Kelly I have seen this name, and it is not in the brief history of Rochester optical companies by Rudolf Kingslake. A version of this is at http://www.ghgcorp.com/mangum/Kodak/Rochester.html I wrote Kingslake on some other matters, and asked about Heesch. He did not answer that question, and my guess is that he did not have the answer. My visit to Rochester led me to believe that Kingslake probably knows more about these obscure companies than anyone else, so any leads on this would be greatly appreciated. -- Peter ============================== ========================================= Binocular List #13, 3/10/98: Teleater, collimation, Mk 41, Asembi ============================ Subject: Teleater From: Fred Watson The `Teleater' is close to my heart, too, so I look forward very much to seeing your article! I always thought that Goerz were the first to go into production with this type of instrument with their `Fago' (although there is that well-known tantalising diagram of a similar optical layout in the 1894 Zeiss `Feldstecher' patent specification). Certainly the early-version `Fago' was around shortly after the turn of the century. I had always understood the `Teleater' didn't appear until about 1912, though I agree the serial number of your early one dates it around 1910. I must confess I have more questions than answers about these little binoculars, and any information you can uncover about their early history would be most welcome. Besides the `Teleater' look-alikes you have mentioned, there were also the `Perkeo' by Voigtlaender, and the `Dainty' by Kershaw of Leeds, UK. Best wishes, Fred Watson ==== From: "Jack Kelly" Within hours after sending out my request for information, I too verified that Goerz had been first on the scene with the Teleater type design in about 1903. (Seeger, Feldstecher) It used a slightly different focusing system but to all outward appearances was the same as a Teleater. In 1908, Goerz offered the Trieder Binocle, Fago which set the standard for those to follow. The Teleater first appears in Zeiss catalogs in 1909. Thanks also for the information on the Kershaw Dainty. Can you provide any more information on the Dainty? Literature copies? Years produced? Photos? Just this weekend, I "discovered" another lookalike by Colmont of Paris, in mother of pearl. It belongs to a friend from Canada who has loaned it to me for photographing. Regards, Jack ============================================= Subject: Collimation From: Charles Orzech This afternoon I took a pair of 7X50 out to the reservior to collimate. I have still not gotten a collimator up and running and decided to try the ancient method of a distant target (about 1/2 mile). It was not as easy as I expected (though additional trouble cropped up with sloppy cells on this relatively cheap bino). Collimation is now OK but I can still tell it is not spot on. Perhaps a good topic for the list would be on using distant targets for collimation? Charlie Orzech ==== ‘Collimation using a distant object' probably means any form of collimation that doesn't use a collimator (?). If your binocular has eccentric rings on the objectives, it is a far more feasible project than if you need to adjust the prisms (often requiring the objectives & oculars to be removed). I have adjusted a few old binoculars, with some success. No doubt not all of them were accurate when I was finished. If you can get a small object in view in both oculars, and then back your eyes away from the oculars (often requiring an adjustment to a decreased interpupillary adjustment); and if that object stays in both oculars when your eyes are half a foot back, those glasses are pretty well collimated. There might be some glasses that could show rotation that wouldn't appear in this test.....I'm not sure. I'd say, you can often get 6x -- 8x binoculars collimated 'good enough' with this procedure. But I would be wary of buying such a glass, that someone else collimated. It's not as accurate or consistent as using a collimator. The problem is, that you might inspect the glass & it seems right; but with extended use a slight miscollimation can give you a whopper of a headache. Of course, if a pro collimates them, and then ships them to you, you’re in the same boat. --Peter ==== Apparently this was the way binoculars were collimated before the invention of optical collimators--by going out to a "target range." I've used the 1/2 foot back technique to adjust for step (vertical misalignment) but was sighting a chimney half a mile away at the edge of the field at 9 o'clock and three o'clock. I can tell they are still not spot on, but using them on the stars (tonight it is supposed to be clear) is the real test. --Charlie ==== Do you have any reference to this? (pre-collimator collimation) It certainly is a method that was & is used. But, since binoculars have almost always been a factory product, I imagine collimators were used in manufacture from the beginning. (2-3x field glasses don't really need collimation). How would you use a vertically oriented chimney to check for step? Using the top edge of it? Peter ==== From: Charles Orzech The method worked quite well, I just got a very nice view of Orion with no eyestrain or double images, even when covering one barrel and removing my hand quickly. I was checking for step separately on a nearby sign in the park (about 8 ft. away). After checking step I swung the binos (tripod mounted) around to look at a house chimney about a half to three-quarters of a mile away. I just kept adjusting the rings so that the chimney appeared at 3 o'clock on the very edge of the field of each barrel when viewed with my right eye. Then I shifted to 9 o'clock and repeated. Then I swung around to recheck step, then back to the target, and on, and on about ten times. On the use of targets for collimation see Bureau of Naval Personnel, Basic Optics and Optical Instruments, pp. 170 and 200. As they note, such a technique is subject to weather (I got rained on) and not particularly convenient. I am still looking for the reference to the invention of collimators around the time of the first world war. As soon as I locate it I'll send it along. Charlie ================================================== Subject: Mk 41 From: "Jack Kelly" A certain Riverboat Captain from Iowa who will remain nameless to protect his safety, recently performed a surgical removal of a pair of 7X50 B&L wide angle binocs form right under my nose here in Portland. He claims that they are commercial rather than military. Does anyone have any confirmation that B&L produced this glass for commercial distribution? When? Does anyone know of a hit man that rides riverboats? ======================================== Subject: Asembi From: "Jack Kelly" I recently acquired a Zeiss DF 80X500 (commonly called Asembi). This is a 12, 20 and 40x80 glass but is of a slightly different design than shown in the prewar catalogs. Seeger makes mention of a WW I version which was not quite so sleek and had sliding sun shades. Mine looks like that model but appears to be newer. I cannot find a serial number on the piece but there is what I believe to be a military property number (Nr. 11199). There is a distributor's plaque right where the top center hinge would be if there was a hinge. Possibly the Zeiss serial number is under that. The plaque is very well made of brass and porcelain with the company name of "Andrew J. Lloyd and Company, Boston, Mass". Has anyone heard of this distributor? Any idea why they would have sold what appears to be a military glass? I have seen an early 19th century telescope engraved with that name, seemingly a French import. Our Man in Boston informed me that it was almost certainly a retailer, not a maker, thereby relieving me of my anguish at just missing this telescope at a sale. My cursory check of the name unearthed no information. -- Peter ==================================== ===================================== Binocular List 14, 3/15/98: Value & price guides; Rating condition; Asst. Feedback =============================== Subject: Value and price guides, Rating system From: "Jack Kelly" I recently exchanged some e-mail with fellow binoc collector Dick Martin. In one of his replies he postulated the following: "We could over time develop a blue book for pricing. Has this been proposed before? Another possibility could be a quality rating system for description of condition which could be used in place of paragraphs of prose. The flip side of all this is that once a source for all this info is available the price structure would become established and the joy of a great inexpensive gun show find would disappear." My response to this is mixed. I frequently wonder about the value of a price guide or at a minimum a rarity guide. The point Dick makes is, however, very important. Price guides have a way of becoming a self fulfilling prophesy. Before you know it, everything moves up a big notch. An interesting corollary occurred recently in my wife's area of interest, Royal Doulton Bunnykin figurines. I used to be able to redeem myself after long absences in search of something for my collection by bringing home a great find for hers. These were usually at some reasonable price. A couple of years ago, someone published a price guide for these collectibles and my source of reasonably priced bribes dried up. In a matter of a few short months, the average asking price in antique shops for these Bunnykins more than tripled! The rarer items increased 10 fold! Today, you never find a bargain. Everyone knows the value. With respect to Dick's other idea, I do have a suggestion to make. I developed just such a rating system for binocs in order to exchange information with fellow collectors. For what it's worth, here is my system. Lets tear it apart and agree on one that makes sense for all of us. It certainly cuts down on the verbiage. BINOCULAR RATING SYSTEM ====== OPTICAL CONDITION 10 - PERFECT 9 - ALMOST PERFECT 8 - SLIGHT HAZE 7 - QUITE HAZY BUT USABLE 6 - HAZE AND DIRT BUT MARGINALLY USABLE 5 - NOTHING BROKEN - VERY DIRTY NEEDS CLEANING 4 - LOTS OF DIRT OR FUNGUS - MAY BE DAMAGED 3 - CHIPPED OR CRACKED BUT USABLE - DAMAGE VISIBLE THROUGH OCULAR 2 - MISSING OR BROKEN LENSES - NOT USABLE AS IS 1 - PARTS USE ONLY RATE COLLIMATION PROBLEMS SEPARATELY (I use an asterisk * to denote glass in need of collimation, e.g.: 7*) ======= COSMETICS (Do not consider missing or chipped eyecups in rating - note separately) 10 - PERFECT - IN THE SAME CONDITION AS CURRENT NEW PRODUCTION 9 - SLIGHT BRASSING ON SHARP EDGES 8 - COVERING UNDAMAGED - MODERATE BRASSING 7 - COVERING UNDAMAGED - MODERATE BRASSING WITH SLIGHT NICKS AND DINGS OR EXTENSIVE BRASSING 6 - COVERING HAS MINOR SCUFFING, HOLES OR TEARS - MODERATE BRASSING WITH SLIGHT DINGS/NICKS 5 - COVERING HAS MINOR SCUFFING, HOLES OR TEARS - EXTENSIVE BRASSING WITH SLIGHT DINGS/NICKS 4 - DAMAGED PAINT OR A #5 WITH BIG DINGS 3 - MISSING OR BADLY TORN LEATHER 2 - MISSING OR BADLY TORN LEATHER WITH BIG DINGS AND DENTS 1 - PARTS USE ONLY Regards, Jack ============ I have written essays for a few antiques publications, including price guide books. The best distributed of these is an essay and a price list on binoculars, and one on telescopes, for ‘Schroeder’s Price Guide’. Overall, I think they are an assistance to the collector, but there are certainly problems with price lists. Worse than losing bargain basement prices is when dealers see that one particular model is worth a fortune, so any similar glass must be likewise; so it is priced unrealistically until some time passes and they dump it. However, I do feel that the idea that price guides torpedo the great bargains is somewhat shortsighted. It certainly does happen, but more often than that, the antiques buyer does not purchase an item for stock because they do not feel there are any buyers for it. If a ‘picker’ goes to a sale and sees a binocular, he’s not going to pay more than a pittance for it, because there is low demand and because he can’t tell if it is a good one. If there is a price guide, he will know if he’s seeing a worthwhile glass. Generally, in antiques, when values get determined, there are fewer great bargains but more objects for sale, and especially more of the rare ones. Price guides bring the stuff out of the basements and motivate dealers to purchase items for stock. Experienced dealers know that information in these guides must be qualified. A somewhat separate issue is that we are interested in objects of great intrinsic value, but low actual value. Most antiques have very little actual value for use or in materials, but are of value because the One Big Rule in antiques is that value is determined not by rarity, intrinsic value, or historical value; but things are valuable because of demand. Binoculars were often extremely expensive when new, and are worth less now because of low demand. Even the most valuable old binoculars would cost more to manufacture today. Price guides are tricky for binoculars, because most old glasses need some overhaul, which is very difficult for the collector, very expensive, and often impossible. So, the value is heavily influenced by how difficult it is to clean & repair, which is impossible to outline in a price guide. The values I put in Schroeders are conservative (less than some collectors would pay). These guides are not a record of results at Christies, but are a guide to the dealer in Anytown USA, who will probably never get a binocular collector through his shop. Obviously, big online auctions are changing this equation (and may well make the price guides extinct). --Peter ===================================================== Subject: Delturisem From: Jack Kelly In the past few months I have come across a Delturisem and a Delturis. Both are wide angle 8X24's from Zeiss. The Delturisem has a typical Kellner eyepiece with small (1.3cm) lenses and the Delturis has a latter wide angle eyepiece design with an ocular about 2cm in diameter. The Delturisem has a very fat prism housing; the Delturis looks like any standard glass of that era. Both appear to have the same wide field of view. The Delturisem (fat boy) is older with S/N 1084522; the Delturis is 1238744. Seeger makes note of the change in physical design form the earlier large prism to the later model. My questions: Were the larger prisms necessary to achieve the wide angle with the older ocular design? Was this a function of glass development? Or, possibly was there just an evolution of understanding about optical design over a 3-4 year span which rendered the large prism design obsolete? If you look at postwar Ross binoculars, they made several wide angle glasses with large prisms, examples being the Stepnada and Stepruva. ============== Larger prisms are needed to maintain even illumination across a wide field, to avoid vignetting. They are much more expensive, so there is always a motivation to reduce size to lower manufacturing costs. The relation of a prism to the ocular type is a very interesting question indeed. ================================ Subject: Pre war Russian glass From: Jack Kelly I have one pair of mystery glasses that one or more of you may be able to help me identify. I bought them at the Great Western last fall and a couple of you saw them there. They look and feel just like a Zeiss 8X40 Delactis but the only markings are Russian. I have compared them to the Zeiss glass and cannot see any obvious differences except for a slightly coarser knurling on the eyepieces. I have two guesses but they are pure speculation. Possibly, they are post war production from captured Zeiss Jena technology. Another remote possibility is that they were produced by Zeiss in the 1930's and sold to the Russian military. At that time, there was a great deal of military exchange between Russia and Germany, with Russia in need of technology and Germany purchasing raw materials as well as using areas in Russia for secret training sites. Any other suggestions? Regards, Jack Kelly =================================== Subject: Andrew J. Lloyd Boston From: "Martin, Dick" I have a Busch Prisma-Binocle 9X binocular, also marked Germany 14508. The Busch Prisma Binocle and Andrew Lloyd - Boston markings are on prism caps with the same lettering style. I don't have the glass with me now but I believe the Germany was in a different lettering. Maybe on the bridge. I would guess the Busch logo and the Andrew Lloyd-Boston were stamped at once at the time of initial manufacture. Looks like your Lloyd was an importer distributor type. You can sleep easier now. Regards, Dick Martin =============== Subject: Images, caption contest I received an amusing binocular related cartoon from Jack Kelly, with the suggestion that we have a contest to write a caption for the picture (but no offer of a prize from his collection). I have abstained from sending images to this list, because my experience with other lists is that they often cause problems. Many people (especially in Britain, it seems) pay by the byte for e-mail; many don’t have the software to view image (in jpeg, gif, etc. formats); and someone eventually transmits an image that they scanned at some impossibly huge file size, which can lock up e-mail programs. So, this message is an offer to send the image, just contact Jack or I. And a reminder that we are looking for a web site, or web sites, to use for images to share with the list. --Peter =================================================== ============================================ Binocular List #15, 3/18/98: Egghead Edition: Resolution; Ocular design ============================== Subject: Resolution Some time ago, I noted that binoculars did not improve resolution compared to monocular telescopes of the same configuration. A response from Bill Cook cast the gauntlet, declaiming.in black & white that binocular instruments increase resolution over monoculars of the same configuration. I was certain that my sieve of a memory retained a paragraph from one of the US Navy tests during WWII, noting that binoculars enhanced contrast & target acquisition, but not resolution. However, I let my native wisdom overcome my usual bravado & withdrew the field, remembering some obscure text about retreat from a more knowledgeable foe. I finally found an authoritative source on the subject.......and darn it, I was wrong (for the seond time this decade, no less). Here is a summation of the article: Binocular Enhancement of Visual Acuity. Ron Cagenello, Aries Arditi, & D. Lynn Halpern. Journal of the Optical Society of America A, vol. 10, #8, 1993, pp1841- 1848. Using both eyes as compared to one, perception of contrast increases by 40 to 50 percent. Reaction time and perception of luminance can increase by 30-70 per cent. Tests by R. Home found 40 per cent increase in acuity with binocular vision at very low contrast levels of one per cent; but when contrast levels were higher than 30 per cent, the increase was about 9 per cent. Other tests, with a chart similar to the standard eye test chart with lines of increasingly small letters, showed improvement of about ‘one half of a line’ in acuity. The published test measured acuity, using block letters on a computer monitor and a Stereographics stereo display program. Letters use lines of varying orientation and spatial frequency (finer & closer lines, or coarser & widely spaced lines). The test subjects viewed the letters through a Minolta 10 x 25 binocular, used backwards to decrease size. (Item of interest: They tested the Minoltas at 65 per cent transmittance). At high contrast levels, all subjects had improved acuity using both eyes. However, at lowest contrast levels, two out of four subjects showed superior acuity using only one eye. All also showed improved acuity with increased contrast at all levels. They also tested for acuity when presenting one eye with a high contrast target, and the other eye with a low contrast target. Acuity improved as contrast to one eye was increased, and ‘performance was governed by the eye that received the higher contrast’. However, in this test, acuity was higher than in the monocular test, so the low contrast eye also contributed. Acuity was increased the most when contrast was the same for both eyes, decreasing as contrast disparity was increased. Pupil size must be controlled, since a larger pupil will reduce resolution because of the aberrations of the eye. Earlier tests covered one eye for the monocular test, which causes an increased pupil size in the uncovered eye. Overall, acuity increased by 11 percent when viewing with both eyes, compared to viewing with one eye (a letter 11 percent smaller could be read). The authors say that this is in general agreement with other studies. This figure might sound low but is significant. --Peter ============================================== Subject: Delturis, ocular design From: Steve Stayton The optical and mechanical design of binoculars being of great interest to me, I can't help but comment on Jack Kelly's observations of the significant external differences in the two versions of the Zeiss 8 X 24 Delturis/Delturisem model. I have not seen these models but I do find the Delturis and Delturisem are shown in the 1923 Zeiss Field Glass catalog (T 260e). I am impressed with the FOV specs for this model, at 8.75 degrees and 8 power it is an extra wide field of view binocular with 70 degrees apparent FOV (assuming typical distortion correction). Without inspection of the glasses in question I will propose some gross generalities concerning binocular design that may explain the differences in Jack's 8 X24's : NUMBER 1. Eyepiece eye lens diameter is determined by three things only: exit pupil diameter, apparent FOV, and eye relief distance. The larger diameter the exit pupil, and the larger the AFOV angle, and the longer the eye relief distance, then the bigger the eye lens (last element of the eyepiece) diameter must be to avoid vignetting. Now, other lenses in the eyepiece may be bigger or smaller in diameter depending on the eyepiece optical configuration and other factors, but the eye lens diameter will be sized by the three parameters listed. So, for Jack's 8 X 24's -- they both have the same 3mm dia exit pupils and if the FOV is the same at 8.75 they both have 70 degree AFOV (35 degree half angle) so that the difference in eyepiece diameter is probably related to differences in eye relief distance. If the earlier model has a 13mm diameter eye lens, it cannot have more than about 7mm of eye relief. If the later model has a 20mm dia eye lens it could (emphasis on 'could') have as much as 12mm of eye relief (still not so great) without vignetting. Now, to achieve a longer eye relief especially with such large AFOV may require a different eyepiece configuration, but without disassembly of the eyepiece it is hard to tell the eyepiece types in this case. My guess is that the later Zeiss 8 X 24 may have a more complex eyepiece design than the earlier model for two reasons: first to achieve longer eye relief (therefore requiring larger dia lenses) and second, to allow for an overall reduction in size of the binocular prisms and housings; which leads me to gross generality No. 2. NUMBER 2: For any binocular with a given objective dia, FOV angle, and magnification, reducing the objective lens focal length (smaller F/number) will allow for smaller prisms and therefore smaller body housings. Complications resulting from reducing the objective F/ number are many. The prisms must have higher index glass to avoid vignetting. The eyepiece will have a shorter focal length (to maintain magnification constant) and this alone will tend to drive eye relief shorter - so to maintain eye relief it will require a more complex eyepiece design. Aberration correction of the optical system will be more difficult and may also tend to require a more sophisticated eyepiece design to maintain performance. To summarize my theory: The second model Zeiss 8 X 24 Delturis in Jack's collection was a design improvement to reduce overall size and improve eye relief. Reduced prism housing size probably a result of shorter objective lens F/ number made possible by using higher index glass for the prisms and improved eye relief resulting in larger diameter eyepiece lenses. Jack, can you confirm a difference in optical eye relief in the two 8 X 24's? Eye relief can of course be reduced by thick eyecups so the eye cups should be bypassed in this measurement. Comments, criticisms, corrections are welcome! Steve Stayton, Tucson, milstay@___rnet.com ====== From: "Jack Kelly" I did a very crude measure of eye relief using a business card and scale. With the binoc focused on infinity, I measured the distance to the ocular when the exit pupil was at sharpest focus. The Delturisem (old, large prism glass with 14mm ocular) had relief of 8mm. The newer Delturis with 18mm ocular measured 11mm eye relief. When I get some time, I'll take out the objectives and measure focal length. Thanks for the ideas, Jack ======= From: Steve Stayton Well thanks for the reply on the Delturis/Delturisem eye relief measurements, that would seem to correspond with my ideas on eyepiece diameters reasonably closely. The theory on the reduced objective F/number in the newer model is more risky as the detail design of prism systems, even relatively simple ones like porros, is full of engineering trade offs. Tweak one area of the overall optical design to reduce size and then some other problem rears its ugly head. Push in on one spot in the design and it bulges out somewhere else! That's a lot of what interests me in binoculars is the wide variety of designs produced over the years for what is basically a simple set of two low power telescopes. Steve ======================================== ========================================= Binocular List #16: 3/25/97. Leached Optics; Decementing; Bushnell 7 x 32 ============================================== A U.S.N. schedule of binoculars from 1944 describes the B & L Mark 18, 7 x 35; and the B & L Mark 24, 8 x 56, as having ‘leached optics’. I’d been looking for an explanation of this for some time, and Earl Osborn came up with it. I hope this encourages others with obscure questions to send them to the list. --Peter From: Earl Osborn Peter, Sorry it's been so long getting back to you, but as always the madness continues here. I really should have answered you all your questions at once but with my work backlog, the home and building construction, an average of 30 e-mails to answer, plus phone calls, at this point even a minute is important. The good thing is that after the move things will be at a more human pace. I believe you ask what "leached optics" were. This was an early attempt at increasing light transmission through the optical system. They were more completely refered to as acid leached or chemical etched optics. The glass was subjected to various chemical solutions in an effort to reproduce the effect that had been noticed, I believe in the late 1800's by Taylor, that tarnished lenses in some cases actually transmitted more light than clear ones. The process is as follows; Most optical glass is composed of a large percentage of silicon dioxide (silica), the residuum being oxides of lead, barium, zinc, calcium, sodium, potassium, and other metals. The method consists, in brief, of dissolving out of the glass the metallic oxides in a thin layer near the surface, leaving in this layer only a porous structure of silica. It was believed that air entered the cavities left by the removed oxides and thus lowered the average index of refraction of the layer. In this way a thin layer of material of reduced index of refraction was formed on the surface of the glass. The chemicals used to dissolve out the oxides were chosen from a consideration of the properties of the glass being treated. As I recall various solutions of nitric, phosphoric and boric acids were used. Now here are several of the disadvantages with this process that led to it's abandonment. 1. Different types of glasses required different treatments. 2. Some types of glasses were very resistant to the treatment requiring a long time to form the film. 3. The process caused a dimming of the glass surfaces in tropical climates and I believe caused a detrimental tarnishing to lead and barium glasses. 4. The fact that water has a dissolving on some components of the glass meant that when a lens that had been treated by the acid process to form a film of low-index material one quarter of a wavelength in thickness, exposure of the lens to atmospheric elements would result in gradual increase in the thickness of the low index layer. 5. If the glass was polished just sufficiently well to remove all visible scratches but not well enough to remove the invisible ones, the small invisible scratcheswould be made visible by the acid process. Therefore lenses to be treated in that way had to be polished for a longer time than ordinary lenses. 6. If the layer was too thick, it sometimes cracked and fell away from the underlying glass due to shrinkage. 7. It was exceedingly difficult to clean without altering it's effective thickness. 8. The increase in transmission was not as good as the flouide process that was begining to be fully developed around the same time (1941/2). Other than that it worked just fine. Take it easy, Earl Osborn Optical Systems osbear@___et.com 3833 N.57th Ave. Phoenix, AZ 85031 (602)247-6131 ======================================== Subject: Decementing objectives UV setting cement is the bond of choice these days when re-cementing doublet binocular objectives. I recently had to un-do a UV cementing job, that used Edmund’s UV cement & a one hour exposure under a horticultural grow light. One week in acetone did the trick. However, some jobs require considerably more effort. Steve Stayton sent me the following instructions for this job. --Peter Separating lenses bonded with UV curing cement, from Norland Products: Immerse in solvent: Methylene chloride -- 100 parts by weight Methanol ------------15 parts Concentrated ammonia (26 Baume or 29% NH3) --- 2 parts The methylene chloride is the active solvent and the other solvents increase its activity. A typical 1 inch dia lens will separate easily (before fully cured) by an overnight soak. A fully cured lens requires a longer soak. Some lenses will start to separate but the solvent will not penetrate to the center even after a long soak. This is due to a very thin layer of adhesive in the center. To separate these lenses a slight thermo-shock is necessary. Warm the lens up to 150 degrees F and immerse it in the solvent combination while still warm. The sudden contraction will allow the solvent to penetrate to the center. Repeat if necessary. Heating in hot oil is another method that is commonly used. Usually it will take 20 to 40 minutes at 400 deg F for the lens to separate. An alternate method is to place the lenses in a vacuum coater and heating them under vacuum until they separate. Remove adhesive from glass surfaces now by immersing in the above solvent bath. --Steve ================================= Subject: Bushnell Xtra-Wide Bushnell has a new model out, their Xtra-Wide 7 x 32. They claim a 13 degree field of view, 700 feet at 1000 yards, implying an ocular with a 91 degree apparent field. See an article on binoculars in Popular Mechanics, April 1998, p57, for a picture of these stubby glasses. --Peter ========================== ============================================= Binocular List #17: 4/1/98. New Improved List. ============================================= Subject: For Sale: For sale: Special shepherd’s binoculars, must be for sighting stray animals because the guy I got them from said they’re great for fleecing sheep. Marked Zowa 30 x 30. Call S. Windlar, 456-7654. For sale: 13 x 53 Varmit Master, only the best binoculars money can buy. Ruby coated front lenses for better resolution. Back Four prisms. Center focus thing and individual focus in one eye. Hinge in middle for adjusting angle of hinge. Sawed off eyecups for glasses or no. Comprehensively multiple coated. As good as Zeiss but cheaper. These are the custom models that you can aim at the sun to start fires with, except on one side where the glue inside the eyeball lens is sort of brown & crackly. Only used twice, at funerals for movie stars, like as good as new except small soda pop spill. New except for that. Complete except no case, also no strap. Caps for lens things are gone AWOL. Other than that, complete. Best offer over reserve. Call Rube, 009-9919. For sale: Binoculars, only markings are Karle Ziess Model JB23. One eyecup brown, the other black. One objective coated, in a aluminum cell, one uncoated, in a brass cell. Leather cover on one side only, but both are painted khaki, so it’s original. Center focus knob looks like a wheel off a tinkertoy. Covers over the body seem to have grown, they kind of hang over the edge a little and are dented at the edges. But, the guy I bought them from said they’re all original, his dad took them off a dead guy in North Africa in 1943, so they’re definitely original. Best offer over $300 (military collectors will snap these up). Call D. Luder, 707-8877. Combination binocular / pipe wrench. Call D. Seaver, 222-2222. Vaguely grey market Zeiss binoculars, various models. Cash or will swap for controlled substances. Call Jim Flam, 432-9876, leave address & credit card number on phone. For sale: Japanese ‘trench binocular’ with Waffen acceptance stamp. Binocular is dirty & worn, but stamp is clear, black and fresh looking. Extensive research shows that this is the only such Japanese glass known with Waffen acceptance stamp. A real piece of history. Call the Mark of the Con Antique Mall, 444-6666. Civil War field glasses. Found buried at battlefield, or near battlefield. Dirty, but not too bad for 130 years old. Look like they might have been used by a Confederate sniper. A real piece of history. Call D. Frahdar, 888-9988. Wanted: Binoculars for surveillance, unusual requirements of use include viewing from dark perimeter into illuminated area. Private replies preferred. Contact Tom Peeping, 007-5555. For sale: Binoculars used by General Patton on D-Day. Bought directly from his boot boy, so definitely the real McCoy. I’m not going to post the marks on these, it might inspire fakers. Call for details, B. Giler, 666-9999. ================================= Subject: Real Binoc Jocks use Excel (TM) By your average computer hater. Back in the good old days, I could count the binoculars in my collection on my fingers & toes. Many years later, I can still count the good stuff on my digits, but I have stacks of junk to boot. So, how to keep track of it all? Fountain pen & graph paper? Journal it into a diary? Hunt & peck on the Smith Corona? Dictate it to the office slave? All of the above? Why not keep it in a computer? It’s practically safe! You can just open a text file & type away. But if you’re planning a really massive accumulation of glass, there’s programs that will cook your goose. If you have no fear of anything, go whole hog & start a database of your stuff. You can start with a worksheet on Bausch & Lomb, add another on Zeiss, then link Bausch & Lomb with Zeiss and practically simulate history. You can start a list of early German makers, add a list of later American makers, who are all German makers who immigrated, and link them so that WWI causes your hard drive to crash! Keep a worksheet of users of German coating technology, add a sheet of makers who used the B & L body style, then filter a list of ‘center focus glasses with eccentric ring collimation imported using fake German names’, and really impress everyone! Databases are cool, but the fact is that real binoc jocks use *Excel* (TM). Because binoculars have numbers that describe them, a spread sheet like *Excel* (TM) is the way to go when you’re cataloging your junk. Just put the name in column 1, magnification in 2, aperture in 3, focal length in 4, date made in 5 & 6, price paid in column 7, and spruce it up with useless garbage like twilight factor! Then, to really wow the dames, you can punch a few keys & derive the average Relative Light Efficiency of your whole collection! Better yet, without lifting a finger, you can string your whole collection ass to aperture & figure the total magnification of the whole mess! Tell everyone how the ratio of age to power of your stuff is practically a constant! And, if you ever accidentally ingest poison & can’t find an emetic, just add up column 7; and in less than a second, the total money you have tied up in your junk is guaranteed to make you throw up! There’s thrills galore with *Excel* (TM)! ================================== Subject: Binoculars for Girlwatching. Anonymously submitted to the list by an unknown person with no name. Most of the guys reading this are too old to care, but one overlooked use for the everyday binocular is for girlwatching. Some of you would rather look at boys, but you’ll have to form your own list. For most of us, while we’re whale watching at the coast, it probably never occurred to us to check out the coastline for sunbathers. Or at concerts, when using your binocs for catching the acts, you can actually view the audience & there are often sights to be seen in that part of the show. Some females actually like sports, and can be found at athletic competitions. The lesson is, don’t just focus on the main event. Binoculars that are suitable for girlwatching include: Miniatures. These really come into their own with this function. Believe it or not, if you haul your 10x80s to the beach on a family outing & scan the sands for vixens, your wife might not understand. Feeble protestations that you are just checking your optics for field curvature are usually met with skepticism. You can only dig yourself deeper in trouble if you maintain that there’s a problem with spherical aberrations that needs attention. It does help if you’re a med student and need to write up an anatomy lab that weekend, or perhaps an athletic coach analyzing the sport. If you can’t get away with these, sign up for a sculpture class and claim that the budget can’t afford a professional model, especially since there’s a nude beach near the vacation spot. Miniatures are a big help for the domesticated. Put those big binocs away for the weekend and get out the miniatures. They are designed to be palmed and used without attracting attention. The common 6 x 18 Japanese Porro I models from the 1960s are perfect for this purpose. Just don’t let your head bob up and down during the volleyball games, and no one will be the wiser. High power binocula