Using Large Format Lenses on DSLR camera
Before a begin try to answer the question and actually what is it all about? After all, now many lenses for the standard 36mm format, the quality is much better. I agree, lenses designed for this format have better sharpness, size, weight and ergonomics. Using large format lenses on digital cameras interesting primarily out of curiosity. If we consider the history of the producing of lenses, it can be noted that a variety of options for optical designs were created in the late XIX - early XX century, this era is considered the dawn of photographic art.
This was the era of great discoveries and experiments. Then the film was a basic standard large format: 18x24cm, 13x18cm, 9x12cm. And in terms of the quality of the lens figured such a thing as image circle. It was believed the larger circle of light has a lens, the better it is. As a high resolution can be obtained using a large format, as the quality of photographs was not so perfect. Professionals used in their work format 18x24cm, and all that less was considered a lot of amateurs.
Since the mid-1930s gaining increasing popularity new format film - 35mm. The new lenses are calculated on this format, have better resolution and corrected on a number of disadvantages of the first generation of lenses. But in the artistic quality of shooting photos and artistic value is not determined by the sharpness and well-corrected aberrations from the picture. The quality of the artistic image is evaluated subjectively, the concept of "like" or "dislike." Here and there is interest in old lenses, have some disadvantages from a technical point of view of the lens.
The first lenses were created taking into account the aesthetic tastes of people of that era - the era of artists. Now, looking at the works of the era admire nobleness pictures, which are often lacking in modern lenses, where they are often a similar character, and does not possess any individuality. Therefore, in the modern era, a host of fans wanting to get some individual picture.
I know of photographers who are looking for lenses with flare, ghosts etc. Art does not have any standards and means of expression are limitless. But as the technology of film photography is gradually replaced by the digital sensor, there is a desire to use these lenses on digital cameras. Consider some of the features of their use.
Jos. Schneider & Co Kreuznach Xenar 105 mm f/ 4.5 on Nikon SLR camera
Especially the Using of Large Format Lenses on Digital Cameras
Lenses designed for large format have a lower resolution. Because they are designed for a large film format, so need less magnification for print, or even print with the ratio of 1:1. For example, the resolution of 36 lines/mm has reproduction lenses that are considered in a large format, super sharp. At the same time, the lenses have small size resolution is not less than 50 lines/mm. If you like per-pixel sharpness, these lenses are not for you. On the digital sensor, due to the small area of the frame, they will seem soft focus.
These lenses usually do not have a focusing mechanism. Since they were placed on the camera, where this function is performed bellows. Therefore, in order to use them in modern cameras, you need to adapt to them focusing mechanism - focusing helicoid, bellows etc. Some lenses can be focused by the rotation of the front element. I have met such a construction on the lenses Trioplan f/ 4,5 10,5cm and Kodar f/ 6,3 10,5cm.
Flange Focal Distance
These lenses are usually long flange distance. So that they can be mounted without problems on any camera retaining infinity. The problem is solved by increasing posterior segment due extension rings or bellows.
If the lens is released before the 1940s, it has no coating and thus has poor resistance to backlit and side light. Which is manifested in low contrast images. It is recommended to use the lens hood. the bigger the better. But even with the hood has to increase the contrast in the graphical editor.
The Color Rendition
Early lenses were calculated for black and white photography and can not well reproduce colors. Some lenses despite age convey color is very well, and some - poor
Quality at All
These lenses will not necessarily be a picture that deserves interest. It may be that it does not appreciate. Be ready for it. Because all the beauty can be seen only on the format that it designed. On the digital sensor will only work its small central part. Already in the 30s of XX century in lens producing there is a certain standardization. Found some good designs for optical systems, which were well corrected from aberrations. And many firms producing lenses under the patent to any particular design: Triplet, Tessar, Planar. But if you want to find an object with some custom retro design, you should look for a lens, calculated for large format.