©1984 The Anstendig Institute


This paper explains why the only known possibility of achieving true precision in focusing has never been brought out by the camera manufacturers.


In 1939, what is probably the most important invention in photography appeared at the Leipzig Fair. From that day until his death in 1970, the inventor, Joseph Dahl, had nothing but trouble from his invention, which has never been made commercially available to the public. This invention, the "Messraster", is the only focusing device capable of achieving absolutely precise accuracy. Since the results of absolutely exact placement of the plane of sharpest focus remain unknown, the world is not yet aware that such precision focusing does make a substantial difference in the most important aspects of a picture. In fact, the placement of the true plane of focus determines the outcome of every other aspect of a photograph.1 Therefore, the ability to achieve absolute focusing accuracy first opens up the true possibilities of photography, both as a creative art and as pure documentation.

In 1904, the Tessar lens was invented. The Tessar made it possible to achieve high optical quality at affordable cost. Lens formulas stemming from the period before the Tessar can achieve just as much optical quality as any modern lens, but only if the lens-elements are ground and mounted with painstaking, prohibitively costly care and precision. The Tessar introduced an easy-to-produce lens formula which is still in use and remains unsurpassed in the quality of sharpness that can be achieved. 

But there is little point in perfecting the quality of lenses if their true possibilities are never seen. Without a precise means of focusing the image onto the film, the real benefits of that lens quality--the real possibilities of photography--will never be known.2 That happens to be the case today in all of photography. It may be difficult for those who have spent their lives photographing to believe, but not a single available camera can focus accurately. It is impossible for photographers to achieve the real potential of their lenses and, therefore, of photography itself. The world has become accustomed to an inferior photographic result and present-day photography is based on theories and concepts, such as those involving "depth of field", that prove to be wrong when absolutely exact focusing is achieved.3

The invention of the Tessar left the field of photography with lenses and camera bodies capable of a high degree of perfection, but with no accurate means of linking them together to realize their true potential.4 The question then is: if focusing precision is all that it is claimed to be, why has the means of achieving it never been brought out by the industry?

Originally, there were many important reasons why the Messraster was never made available to the public. The most easily understandable reason is that manufacturers would have stood to lose more by introducing it than the Messraster itself would have earned. Many other products which cost a great deal to develop and brought in substantial revenue would have become obsolete. If a camera has interchangeable focusing screens, the Messraster is interchangeable with the other focusing screens. But, to realize the Messraster's potential, it is necessary for the position of the film-plane to be perfectly aligned with the position of the focusing screens. To be sure of this, a technician has to check and adjust the alignment of the camera for which the Messraster is purchased. A more costly precision would, therefore, have been necessary in many camera-bodies.

The Messraster would have been quite expensive to manufacture in those days. The cost of the Messraster would have been a good quarter or more of the cost of the whole camera, which would also have cost more to manufacture due to the greater precision demanded by the Messraster. The difficulty and expense of manufacturing the Messraster has been eliminated since then by new techniques developed, during the 1960's, for mass-producing other focusing-screens.

Today, the Messraster is not being brought out because the industry has invested billions in the development of auto-focusing devices, many of them even based on, but not as accurate as, the Messraster. Because their results are at best only approximate, the use of these devices assumes a belief that, since depth-of-field will take care of the resulting inaccuracies, there will be no difference between photos with such imprecision and photos that are precisely focused. By making the public aware that absolute accuracy in focusing and precise placement of the plane of focus will make an important difference in the appearance of their photographs and by introducing a simple device that achieves such accuracy, the industry would drastically reduce the demand for most of those new auto-focusing devices. Manufacturers, therefore, have little interest in making the public aware of the realities of optical physics.

When the Messraster first appeared, there were other important reasons for efforts to suppress it, some of them quite difficult for our present society to understand.

The photo-optical industry has always been the prestige industry of the world. It used to be the case that, if a country wanted its other industrial products to be taken seriously, it had to first prove itself in the quality of its optical industry. The success of German and Japanese products comes directly from the success of their photo-optical products. Japan understood this so well that, after the war, the government itself set up a testing institute that checked every single optical product before it left the country.

The German temperament has also placed a great deal of emphasis on concepts such as prestige and "saving face". In 1939, the Leica and Contax cameras were the prestige cameras of the German photo-optical industry. At that time, these cameras were quite primitive rangefinder cameras that could only focus quite inaccurately up to about six yards. Their viewfinders presented a dull, dark, difficult-to-see image. Other types of cameras were even worse. Because of the shortcomings of their cameras, manufacturers developed and energetically fostered systems of photographing based on concepts of depth-of-field as depth-of-focus. However, depth-of-field really has nothing to do with sharpness. It describes tolerable unsharpness, i.e., how far in front and in back of the true plane of focus the degree of unsharpness can be expected to remain tolerable to the “average” viewer. By definition, depth-of-field depends on being able to determine and precisely place the true plane of focus, since the boundaries of unsharpness extend in front and back of it. But precise placement of the plane of focus was not possible. The industry therefore pushed the idea of depth-of-field being the same as depth-of-focus in the sense of sharpness in order to sell their cameras.

Then, along came Joseph Dahl who brought out a truly precise, easy to use, absolutely focal-point-exact focusing device, which was judged the "basis of an exact photography” by the leading optical institute of the world.5 Dahl wanted the industry not only to bring out the Messraster, but 1) wanted them to describe it as what it really is, namely, the only exact means of focusing, 2) wanted them to tell the truth that their focusing devices are inaccurate, 3) wanted the truth told about depth-of-field, 4) wanted the public educated to the fact that it makes a difference when the most important point of a picture is focused with exact precision, and 5) demanded even finer manufacturing tolerances in cameras because of the greater precision of the Messraster's focusing ability.

All of these demands still need to be carried out today. They go along with the technical advance embodied in achieving true focusing accuracy and are truly every photographer's birthright. Carrying them out at that time would clearly have been a near total disruption of the whole industry. In 1939 photography and cameras were quite simple. There were none of today's many convenient, but expendable features, such as through-the-lens metering, etc., to confuse the issue. Everything was clear-cut. The world had lenses and camera bodies, and the next important step was to unite them with real precision. The primitive early Leicas and Contaxes were the finest cameras. The others had either worse provisions for focusing or none at all. But the owners of these cameras had been fed the idea that they were making pictures approaching what was optically possible.

If the world had learned that absolute focusing precision is not only possible, but actually makes an enormous improvement in even a simple family-album type portrait photograph, the owner of the only patent capable of achieving exact focus would have controlled the whole industry. That man would have been able to decide who could use his patent and thus dictate the policy of the world's most prestigious industry.

Furthermore, the manufacturers would have lost face for having propagated concepts which they knew to be optically wrong. They would be faced with enormous retooling costs to bring out new single-lens-reflex cameras that could use the Messraster. Since their rangefinder and other cameras were selling extremely well, they would not only have had the expense of developing a new product, they would have lost the revenues from those products already on the market. Under all of these circumstances, the German photo-optical industry not only did not bring out the Messraster, but militated quite strongly against it and its inventor.6

Above and beyond all of these considerations, a major factor in the suppression of the Messraster as well as the truth about focusing is the general tendency of all industries to resist making radical changes in what they are already manufacturing as well as the similar tendency in the users, particularly professionals, to resist relearning and changing the way they have already been doing things.

The author met Joseph Dahl in 1960, had Messrasters installed in all of his cameras, and, realizing the importance to the world of this device, worked with Mr. Dahl for a decade without remuneration trying to make the Messraster known and researching and demonstrating the effects of precise placement of the focal-plane (the sharpest plane of focus). Some success was achieved in interesting manufacturers in the Messraster. Some manufacturers, including Nikon, wanted to bring it out. Joseph Dahl decided to manufacture it himself, but in 1970, just as everything was ready to begin, he died.

The author, who had returned to America in 1969, was sure the industry would then bring out the Messraster and went on to other fields of work. Unfortunately, he was wrong. In the interim, the photo industry has gravitated towards more and more automation and has been investing heavily in developing automatic focusing. For customers to be sold on automation, it is necessary for them to believe that approximation is enough and that, for their photographic needs, truly precise results will not make any appreciable difference. There has also been a recent trend towards simple cameras using pop-in type convenience film packages, many of which have no focusing provision and rely solely on the false concepts of depth-of-field. Even most makers of prestige cameras have added one or the other of these types of cameras to their line. The camera manufacturers, therefore, have little to gain in waking up the photographic world to the need for real focusing precision, as it would make many of their products obsolete.

The world has lost enormously by the absence of a means of achieving absolutely exact (focal-point-exact) focusing. The whole public, laymen and professionals alike, has never been able to see and compare for itself the results of real focusing precision. Society remains uneducated in the true psychological aspects of visual reactions to photographically produced images as well as much more that pertains to the psychology of seeing in general. Without having studied examples and comparisons of perfectly focused photographs, no one can really understand photography.


1 The Anstendig Institute possesses precision-focused photographs which demonstrate and illustrate focal-point-exact focus with all types of photographic subjects.


2 Even less high-quality lenses will perform best when focused precisely. There are some lenses, called soft-focus lenses, in which the sharpness is purposely mitigated to produce a somewhat diffused, “soft” image which can be flattering in portraits of people with wrinkled skin or skin blemishes, for example. But even these lenses produce their most effective results when they are carefully and precisely focused.


3 The Anstendig Institute's other papers on photography describe the Messraster, the effects of focal-point-exact focusing, and why other focusing devices cannot focus accurately.

4 It is important right from the beginning to emphasize that I am speaking of something--the effects in a photograph of true focusing accuracy--which the reader has never has the opportunity to see and carefully compare with prevalent photographic results. It is important, therefore, that the readers not form an opinion of the importance of absolutely exact focusing precision until they have had an opportunity to see photographs made with such precision. It should also be emphasized that, while writing about it may make focusing precision sound like a highly technical matter, it is, in reality a very simple matter and, with the Messraster, quite easy to achieve. In fact, the Messraster actually frees the photographer to concentrate on everything else about the picture.

5 This determination was made by Prof. Dr. Weidert of the Optical Institute of the Technical University of Berlin.

6 The history of the Messraster and its inventor is the subject of another paper of The Anstendig Institute.



The Anstendig Institute is a non-profit, tax-exempt, research institute that was founded to investigate stress-producing vibrational influences in our lives and to pursue research in the fields of sight and sound; to provide material designed to help the public become aware of and understand stressful vibrational influences; to instruct the public in how to improve the quality of those influences in their lives; and to provide research and explanations for a practical understanding of the psychology of seeing and hearing.