Emil Busch Bis-Telar 550mm f/7

[arri]

A very early telephoto lens, made in the 1910th I guess. Four elements in two groups.
It were the first tele lens with a fixed separation between the lens cells.
In this focus length it is quiet rare, the most foci you can find are 270mm, 340mm and 400mm for the popular sizes 4x5", 5x7" and 8x10

The 550mm version is for a 11x14" size camera.
The Bis-Telar has a very short oo extension of 320mm

For the test shot I used the Fuji X-Rayfilm UM-MA in Wehner Developer, Sinar Norma 8x10" with rear lens shutter, Film size is 18x24cm.

Here two pictures of the lens, I made a lens board adapter to use aluminium discs with 100mm diameter. I cut the thread directly into this discs. This makes it much more simple because I don´t need extra mounting rings. The 100mm diameter ist much smaller than a Sinar board and saves a lot of space.

240017 240018

Here is the sample shot I made with the lens. I used f/22 The leafs are not 100% sharp because of the windy weather and the 1/2 sec. exposure time.

https://live.staticflickr.com/65535/53006424460_a7dc83b57f_k.jpg

[domaz]

I'm kind of surprised a 550mm telephoto design lenses could cover 11x14. Compared to modern offerings like the Nikon telephotos anyways that don't cover near that much at that focal length. Although I guess there was a variation of the Nikkor-T that could cover 8x10.

[xkaes]

I'm kind of surprised a 550mm telephoto design lenses could cover 11x14. Compared to modern offerings like the Nikon telephotos anyways that don't cover near that much at that focal length.

I'm sure it's just the lens design. Modern true-telephoto lenses, from Nikon & Fuji for example, can have angles-of-coverage as small as 25°. Even simple Tessars are around 60°.