# Sonnar formula lenses on mirrorless cameras: post your shots.



## BrianV (Jan 17, 2013)

The Sonnar formula lens appeared on the market for the Contax RF camera of the 1930s. The design optimized transmission of light by minimizing the number of optical surfaces. The lens is in three groups, two sections. The front section is a telephoto lens with a focal length about 2.5times the focal length of the completed lens. The rear section is about the same focal length of the completed lens. The spacing between the two sections is small, and the overall lens is very compact. The back-focus of Sonnar lenses is relatively short, and lenses with focal length less than about 100mm never made it to the world of SLR's. Basically, they are in the domain of the mirrorless camera.

The Nikkor 5cm F1.4 is the first Sonnar lens faster than F1.5, appeared on the market in 1950. Made in Leica thread mount, it has an 18" minimum focus. Also available in Nikon "S-Mount", and can be used with an adapter on mirrorless cameras. The RF coupling on the LTM lens goes to 0.9m, can be modified for 0.7m
On the EP2, used with an adapter, the 18" minimum focus is quite useful. Wide-open, lighting from a flat-panel display at a Museum.


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## Helen B (Jan 17, 2013)

40 mm Sonnar on a Rollei 35S Kodachrome 64:


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## BrianV (Jan 18, 2013)

An online article on Sonnar lenses states that the 40/2.8 Sonnar was originally designed with front-cell focus, like the Rollei 35 Tessar. The designers were not happy with the result, redesigned the camera to focus the lens as a unit. The front-cell focus lens eventually found it's way to market as the Sonnar 40/3.5 on the A26 instamatic camera. I picked up a broken A26 with the idea to hack the lens into a new mount.

Carl Zeiss Jena 5cm f1.5 Sonnar from 1936, converted to Leica mount. Wide-open.




Gunston Hall


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## Ron Evers (Jan 18, 2013)

This list of such lenses my be helpful:

Antique and Classic Cameras


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## BrianV (Jan 18, 2013)

I have 14 of the lenses on that list. Also have 6 more in different mounts.

This one is not on the list.







A Can-Nikkor 50/1.5. Made from the front section of a Canon 50/1.5, rear-Triplet of a Nikkor 5cm F1.4 and set in Leica thread mount, RF coupled.


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## BrianV (Jan 30, 2013)

This is an early Sonnar, 1934 5cm F2- converted to Leica mount using a Jupiter-8 focus mount. Modified to close-focus to ~0.8m. Wide-open, and close to minimum focus. The glass on the F2 Sonnars is soft, like the glass on the Leica Summars. The F1.5 Sonnar glass is much more durable. This example is very clean.


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## BrianV (Jan 30, 2013)

This is with a 1934 5cm F1.5 Sonnar, converted to Leica mount using a Jupiter-3 focus mount. TheSN is in the 160xxxx range: the eariest than can be converted. Earlier lenses (1932 and 1933)  used a different fixture, and cannot be easily converted. Wide-Open at F1.5.


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