Czapski. by Larry Gubas Siegfried Czapski joined Zeiss on a recommendation from Helmholz in 1884 and quickly evolved into Dr. Abbe’s immediate assistant. He worked to take the formulas and ideas that Abbe had 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 firm's 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. ================================================== SIEGFRIED CZAPSKI, by F.F. Martens Commemorative Address, delivered at the meeting of October 18, 1907. Translated by Ilse Roberts and Peter Abrahams. Portions of this text are incompletely translated, into phrases that are more of a word for word translation. Only the first section was translated, the second half was on Czapski as manager. Copyright 1997. Not three years have passed by, since Siegfried Czapski stood at this place to commemorate the life and work of his mentor, Abbe. Now the words of the younger one are forever silenced, for on July 29 1907 he died of complications of a not too severe operation. Siegfried Czapski was born on May 28 1861 in Obra in the province of Posen, completed his studies at the Gymnasium at Breslau and studied in Goettingen, Breslau and Berlin. In Berlin he was one of the students of Herman von Helmholtz; and his disssertation: “About the thermal variability of the electromotor force of galvanic elements” (1) earned him his doctorate in 1884 in Berlin. In the spring of 1885 Helmholtz recommended him to Abbe who was looking for an assistant. So, Czapski moved to Jena, where he spent all his working life. After a short time he was hired by Zeiss, and 1891 he became a member of the management of the Carl Zeiss Company. After Abbe’s death he became the representative of the Carl Zeiss Foundation and member of the management of the glass manufacturer Schott and Associates; the same year he received the Prussian Doctor title. In 1887 Czapski married Miss Koch, a niece of Mrs. Abbe, and a granddaughter of Professor Snell, who brought Abbe to Jena. 8 children were born to them, whose father’s strong hand is too early taken from them. CZAPSKI AS OPTICIAN Of Czapski’s numerous papers, three are the most important ones. Right at the beginning of his career he described the manufacturing of the new Jena glasses and the advantages they offered, namely in regards to freedom from color. (3) He also wrote an extensive study about the limits of microscopic efficiency. (12) He gave a fundamental paper in Berlin about the new prism telescopes at the “German Society for Mechanics and Optics”. This paper, as most of the smaller publications, deal with Abbe’s inventions. Czapski himself created an improved Cornu Polarization photometer, (16), as well as a ‘double circle’ crystal goniometer. (17) With the latter, for the first time a method was used to exempt all surfaces of the crystal except for one, not by blackening of the planes but by dimming in the image, which the telescope creates from the crystal, in front of the pupil of the observer. The monographs of Czapski’s are in importance far exceeded by the book published in 1893: “Theory of Optical Instruments after Abbe”. (18). We find here the development of the laws of image reproduction from the co-linear relationship of object and image plane. The only exception is, that homocentric rays, i.e. rays that converge in one point, correspond to each other definitely in the object and image plane. Nothing is assumed about the type of realization of the image, in contrast to the (customary since Gauss) derivation of the laws of image creation for paraxial rays, i.e. for small objects and for small lens openings. Czapski supposes in the object plane an unlinear, but in the image plane a linear, system of coordinates, and not only figures the position of the images and the importance of the of the focal lenses, but also the lateral magnification, the depth magnification, and the convergence relationship: even the laws about the structure of optical systems result. The realisation of this image without limitation is possible using flat mirrors; with centric spheric planes only the rays which are indefinitely close to the axis fulfill the conditions of co-linear image creation. For the enlargement of image limitations Czapski gives the formulas communicated by Abbe in his lectures, which permit the calculation of different aberrations introduced through each plane; the sum of the aberrations of one kind, stretched over all planes has to be vanishingly small. Such error formulas are mostly used for chromatic aberrations, the spherical aberration for the objects which are lying on the axis, and the spherical aberrations of the focus length (deviation from the sine condition). While meeting of the above conditions creates usable telescope objectives, for microscope objectives only the trigonometric calculation of the rays that exit from one axis point and are tilted strongly towards the axis lead to the knowlege, and continuous change of the planes to the diminishing of image errors. If these rays meet the sine condition, good images can be predicted for the rays which exit from the edge of a small object. For photographic objectives the objects are so large that the calculation of the rays exiting from the axis points in connection with the the sine condition is not sufficient; and here the much more difficult calculation of bent rays is unavoidable. In the Czapski book, the theory of the entrance and exit pupils of an optical system is explored for the first time. The totality of the ray bundles can be divided into: 1) ray cones with apex in the object or image points, and base in the pupils (stops); 2) ray cones with base in the object or image point and apex in the pupils. For the astronomical telescope the objective is the entrance pupil; the width of the ray cones 2 and therefore the f.o.v. is independent of the diameter of the objective opening. Quite different is the Galilean telescope used in most opera glasses: here the objective acts as a window, through which one looks onto the street. Here too the influence of the aperture & field stops on the brightness of optical instruments is treated in a clear and extensive manner. Since it is impossible to increase the image plane brightness of light sources by optical means (specific brightness, temperature of the rays), it is required that the ray cones whose apexes lie in the illuminated planes have rather large angle openings (or bases). The projection screen, the photographic plate, and the retina of the eye serve as an illuminated plane. The illumination of the retina is in the best of cases the same as if the light source were immediately in front of the pupil. Besides f.o.v. and brightness, the stops also have great influence on aberrations. Though Czapski did write on geometrical optics, he, in spite of all the difficulties and successes thereof, never forgot that light rays are of a physical nature, that geometrical optics creates necessary ideas, but only when it takes into consideration the theory of refraction does it also create satisfying image conditions. These thoughts are, as is well known, especially important for the microscopic image. The objects have essentially a grid structure and bend the passing rays. The microscope objective projects in its upper focal point an image whose these refractive spectra are spatially separated. These spectra require the light be distributed by interference, in the image plane of the ocular of the microscope. If only the unrefracted diffraction spectrum through the grid comes into play, a graduated brightness can never be achieved in the image plane of the microscope. The microscope objective then has to have a large opening, so that it at least takes in the first diffracted image [Beugungsbild]. This theory, as well as the sine theory, was voiced by Abbe and Helmholtz at the same time, and confirmed by Abbe in many exacting experiments, as is well known. The recognition of the the important role of the stops was also useful for the construction of a number of very perfected measuring instruments. An special mention is earned by the Abbe Fokometer. When describing it, Abbe gives, though not in so many words, a devastating critique of the usual method of the focal point fixation. CZAPSKI AS FACTORY MANAGER. (Had rather socialistic ideas , very worker friendly, pensions, etc.) ================================================= Stereo microscopes in the 19th century, C. Zeiss model produced in 1897. Horatio Greenough, American in Paris, wrote Abbe & Czapski in 1892 suggesting designs for a stereo microscope. His name was used for a low power stereo microscope designed & developed by Czapski, but Greenough was dissatisfied & ‘disowned’ it in 1907. It was improved by Leitz in 1919 with wide diameter, corrected oculars & larger objectives. [Bracegirdle: 1910, Leitz Greenough stereo microscope first offered] (Singer, Hist. Tech., vol. 7 (ed. Trevor Williams), p1354, Oxford: Clarendon, 1978 ================================================== BIBLIOGRAPHY OF CZAPSKI, AS FOUND WITH ‘FIRST SEARCH’ Czapski, Siegfried, 1861-1907. Ueber die thermische veranderlichkeit er electromotorischen kraft galvanischer elemente und ihre beziehung zur freien energie derselben :inaugural-dissertation zur erlangung der doctorwurde von der philosophischen facultat. Leipzig: Druck von Metzger & Wittig, 1884. 40 p. ; 23 cm. Inaugural-Dissertation--Friedrich- Wilhelms-Universitat zu Berlin. (Subject: Electric motors. Electric machinery.) Theorie der optischen Instrumente, nach Abbe. Breslau: Trewendt, 1893. viii, 292 p. ill. Reprinted from Handbuch der Physik, by A. Winkelmann, Band II. Ueber neue arten von fernrohren insbesondere fur den Handgebrauch. Berlin: L. Simion, 1895. 40 p. diagrs. (telescopes) Grundzuge der Theorie der optischen Instrumente nach Abbe. (2nd ed.) 2. Aufl. unter Mitwirkung des Verfassers und mit Beitragen von M. von Rohr hrsg. von Dr. O. Eppenstein. Leipzig: J.A. Barth, 1904. xvi, 479, [1] p. illus., diagrs. 26 cm. "Sonderdruck aus dem 'Handbuch der physik' von A. Winkelmann, band v." Grundzuge der theorie der optischen instrumente nach Abbe. (3rd ed.) 3. aufl. unter mitwirkung des verfassers und mit beitragen von M. von Rohr hrsg. von dr. O. Eppenstein. Leipzig: Czapski, Eppenstein, 1924. xvi, 479 p. illus., diagrs. 26 cm. "Sonderdruck aus dem 'Handbuch der physik' von A. Winkelmann, band VI." Ernst Abbe als Arbeitsgeber. Tubingen: H. Laupp, 1907. 40 p. 24 cm. (Staat und Wirtschaft, 2. Arbeitshefte Staat und Wirtschaft.