1949 Leitz Centenniel Book Part II
This is the cover of one of the handful of hybrid copies made by Fred and Jo Mazzulla of Stenger’s 1949 book “Die Geschichte der Kleinbild Kamera, bis zur Leica” in which the translated text lies side by side with the original German. Scan from the LHSA Archives done by Doug Drumheller for this
To celebrate LHSA's 50th Anniversary, here is the second of three parts of a special translation of Erich Stenger's history of the Leica Camera, originally published in 1949 in German for the E. Leitz Company's 100th Anniversary. The translation was arranged for by Fred and Jo Mazzulla, and issued in a limited edition volume with side-by-side German and English language pages.”
∙researches leading to the leica
Who would be better qualified to give information than Oskar Barnack, the inventor himself ? Let us give the floor to him first:
"How I came to build the LEICA. Well, I'll really have to go back two and a half decades. At that I was eagerly photographing with my 13 x 18 cm. camera with six duplex dark slides and large leather case, which looked like a carpet-bag. That was a lot of baggage when I went out on a Sunday to roam the Thuringian Forest. Panting up the mountains the idea must have occurred to me; at any rate, I still remember how I started experiments, dividing up the 13 x 18 cm. plates into small sections, trying to get 15 to 20 exposures on one plate by means of a lens with a short focal length and a special device. But it was a complete failure. The enlarged pictures were by no means nice to look at (on account of the coarse grain). I dropped the whole idea for the time being, although the realization, 'small negative, large picture' had already been born.
“In the meantime a change took place in my occupation as I entered the Optical Works of Ernst Leitz, Wetzlar, in 1911. Here my work, among other things, also included cinematographic camera technique. In 1912 I built my first motion-picture camera and I now rapidly approached the right way of solving the problem, owing to the fine grain of the motion-picture film. An enlargement of the motion-picture format to postcard size was not bad at all.
“But in the meantime my standards had gone up. The postcard and, still more so, the 6 x 9 format, are all right for family pictures, but the real photograph does not begin under 13 x 18 or, better yet, 18 x 24 cm. Even these sizes appear quite small after seeing pictures 50 cm. wide. There is no denying it, the larger the picture the more it seems to create a plastic and natural effect. For that purpose the motion-picture format was too small. Since the motion-picture film could not be made wider because of standardization, I had to make the other dimension as long as feasible to get the best possible utilization. I took twice the motion-picture format right away; that is 24 x 36 mm., and it was quite effective. That was how the LEICA format was found. In other words, it was not the product of brain-racking thought for months on end, as was quite often the case with camera parts which did not show it at all. I still consider the 2:3 side ratio to be the best and most serviceable.
“That was when the actual designing of the LEICA began. I gave full rein to my predilection for the unusual and novel. I was not bound by an order or told to work in a certain direction, as is common in modern designing offices, but it was more of a private hobby. By thus indulging in my own likings, not heeding to accepted methods and using almost nothing which had so far been considered indispensable to a good camera, this new type of camera was created. In its main features it was the same then as it is today. The only differences were that in the first model I did not use an adjustable focal-plane shutter but one with a fixed slit 4 cm. wide with several springs to operate it and the camera was not yet equipped with daylight cartridges. But apart from that everything was there. Particularly the coupling between the film and the shutter.”
First Experimental model (UR-LEICA)
“For many years: I worked with this model and still have many pictures from that time. The further development of the model was prevented for the time being by the outbreak of the World War in 1914. But on the basis of many pictures taken during the War, I gained much valuable experience so that, when the question of production was raised later, I could come out with the blueprints within a fairly short period of time.
“The following still had to be designed: a rangefinder for close-ups, the indispensable equipment of a camera without ground glass screen; then an absolutely dependable adjustable focal-plane shutter which could be cocked by an internal mechanism; and finally a way of loading the camera in daylight by means of cartridges. The viewfinder was also built at that time. After these problems had been solved, satisfactorily, I think, there remained only one big question: a suitable lens. Naturally it had to be of outstanding quality, for an enlargement up to ten times the negative size was the minimum requirement.
“That is where the work of Professor Dr. M. Berek started; he succeeded in computing an anastigmat lens with a light-passing power of l: 3.5 and f/ 50mm., which was at least equal to the very best of its kind. This solution contributed substantially to starting the camera on its way. Slowly, at first, then faster and faster, and that with a remarkable increase year after year. This is what you may call sound development.”
LEICA, Model II, first model with coupled focusing
It would be quite beside the point to suppose that this first model of the LEICA was created by tinkering about long enough and then, by accident in a way, became a generally usable miniature. Barnack’s ways were well-considered, the result of mature thought. We have become acquainted with his reflections through a recent publication of the man who took part in the experiments in the same field and contributed substantially to the final success of the new creation. It is Professor Max Berek (born 1886 in Ratibor, since 1912 working with Ernst Leitz in Wetzlar), who computed the LEICA lenses and probably also had some influence on Barack's considerations. Let us listen to his account: “The building of the LEICA was something wholly new. Here the miniature picture for the first time and intentionally served the purpose of a certain pictorial effect. Uninfluenced by theories, Barnack had noticed himself that only large pictures could make an artistic impression on the beholder. The reason therefore was well known. In order to obtain a natural plastic impression, that is a vividness approaching that of natural vision, both eyes should be in the proper perspective center in relation to the picture. From this finding Barnack at first drew the conclusion of preferring the largest practicable picture formats, because those admitted of a sufficiently large viewing distance without subsequent enlargement. But the cameras he had to use continued to grow rapidly in size with his self-imposed demands on the vivid impression of the pictures, and finally a serious asthmatic condition made it impossible for him to burden himself with such weights on his excursions. But he also noticed something else in these pictures: they contained a richness of detail which in viewing them from the distance prescribed by the focal length of the lens could not be distinguished by the eye and thus was not utilized. ‘How can I do it differently and better? ‘was his motto. He wanted to adapt the perceptible details of the picture to natural vision and entered upon the following considerations:
“On account of the particular construction of the retina, the human eye can distinguish only such details of objects of any shape or form -- aside from special cases -- as appear to it under an angle of one minute of arc. However, usually this limit is not fully utilized, so computations for easy, unstrained perception may be based on 2 arcminutes.
On a circle with the radius 1 this corresponds to an arc of w = 0.0006. In order for details of such fineness to be shown on the film a focal length f must be used which satisfies the relation f x w = d, d being the selectivity of the sensitive layer after development. If the selectivity is supposed to be d = 0.03 mm., f equals 50mm. This focal length was taken as a standard basis for the projected camera. Now the supposed selectivity corresponds to a picture element which takes up an area of [d/2]2 π = 0.0007 on the film. The problem was to find the number of independent elements necessary for a picture with satisfactory fineness of detail. O. Barnack solved this question by counting the screen elements in screen printings leaving a unified visual impression on the eye. He arrived at a mean figure of about 1 million picture elements. Of course, such a number need not be taken too exactly, and moderate deviations either way are insignificant; but in that manner he obtained a statistical mean value on which he could reasonably base his further design. Now, with the supposed valued 1 million picture elements covered an area of about 0.0007 x 106 = 700 mm2. So, this would have to be the size of the practical picture area. If the very attractive ratio of 2:3 is chosen for the sides, a format of 22 x 33 mm. would result in a picture area (726 mm2) which is practically identical with the value required. This clinched the use of the motion-picture film; in consideration of its standard measurements the format of 24 x 36 was chosen instead of the computed value because the deviation was insignificant. That is to say that this ‘LEICA-Format' somewhat over 1 million picture elements are represented, assuming a selectivity of d = 0.03 mm.
“Now came the mechanical work on the camera. Here O. Barnack realized from the very beginning that because of the intended heavy subsequent enlargement the mechanism of the camera would have to be of the greatest possible precision and that he must not, under any circumstances, make the mistake of relying on the great depth of field resulting from the relatively short focal length of the standard lens. In 1913 two of the cameras were completed; this UR-LEICA aside from insignificant details was exactly like the standard LEICAs which are now put out. Unfortunately no suitable lens could be found at first. For the time being O. Barnack worked with a Zeiss Movie Tessar 1:3.5 f = 5cm., which, being designed for the motion-picture format, did not, however, work satisfactorily with the LEICA format which was twice as large. Later O. Barnack used a Leitz Micro Summar 1:4.5, f = 6cm. which, again, did not give full satisfaction. The first World War brought all work on the camera to a standstill. But immediately after its end, O. Barnack again turned to his favorite work. However, even then it was still his personal hobby, and large-scale production was not yet under consideration. During that time the range finder was designed, the film advance mechanism and several other things were perfected; but his primary concern was still finding a suitable lens. Here the author of this account, who was associated with O. Barnack by common occupational interests, and also, was on very friendly terms with him privately, came to his aid. The first LEICA-lens, Elmar 1:3.5, f=5 cm. was created-which is still used as a standard lens.
LEICA. Model I with universal Viewfinder and interchangeable objectives with focal distances of 3,5 – 13,5cm.
It was followed by Elmar 1 :3.5, f = 3,5, which, when used with the 24 x 36mm. format, approaches the properties of a wide angle lens and with a picture element of d=0.03 mm. yields a selectivity of about 3 arc-minutes, which in such pictures is not considered insufficient. The lenses of 10.5 and 9 cm. focal length, which were added later, already reach the extreme limit of the selectivity of the human eye; finally followed the lenses with 13.5cm. and even greater focal lengths which decidedly show beginning telescopic properties because their selectivity considerably exceeds that of human vision.
Original
translated
manuscript
“The inclusion of the LEICA in the production program was brought about by external circumstances. The inflation in Germany which followed upon the first World War had caused a specious boom in all branches of industry which soon left the world saturated with industrial products. On the introduction of a stable currency in Germany in 1923 the specter of unemployment made its appearance. It invaded the optical industry to a very considerable extent. Under such conditions it was the endeavor of the head of the Leitz Works, faithful to the traditional social-minded policy of the firm, to continue the employment of all workers and employees, even if great sacrifices should be necessary. In this situation the LEICA was called to remembrance. True, prominent expert photographers to whom it had been shown, almost without exception had dissuaded from the venture, but in 1925 production was started, though on a very modest scale. It was an entirely new field for the Leitz Optical Works, for they had hitherto devoted their production exclusively to microscopes. But then the LEICA now benefitted from the high precision-standards of microscope building. And soon there was a big surprise: the demand for the new camera grew with amazing rapidity; soon the plant had to produce hundreds and later thousands of units a month. What, then, was the reason for the enthusiasm with which the public, all prominent experts notwithstanding (and soon even a part of them) turned to the new camera? After all, the price of the LEICA, because of the first-class precision work that went into it, was in a range with the best cameras then obtainable. The secret was that even in the hand of the inexperienced this camera almost by necessity brought amazing results. This was a consequence of the practical combination of negative format, focal length, and relative opening of the standard lens, method of focusing, and, last but not least, the precision-built mechanism.”