Ricoh GXR: M-Mount Unit with Zeiss 21 mm

Archive

Note: At the end of 2016, I sold my Zeiss Biogon 21mm f/4.5 lens in favor of the Leica Elmarit-M 21mm f/2.8 ASPH. lens in order to have less trouble and work with color shading when the lens is used at the Leica M (Typ 240). I am therefore no longer able to update this page or to answer questions about this lens.

After Ricoh's official announcement of the M-mount expansion unit, I decided to buy one, although I had not intended to do so originally. Here are my first personal experiences with the lenses that I bought (or tried to buy). This page is devoted to the Zeiss Biogon 21mm f/4.5 lens.

Expanding the Equipment

After I had acquired the M-mount expansion unit in mid-October 2011, I decided to also expand my range of lenses into focal lengths that I already own in the form of A12 camera units. This was caused by the observation that I was too lazy to exchange units. Exchanging lenses only seemed much simpler and also simplifies the equipment that I carry around with me.

This decision turned out to become a very expensive one, because both of the Voigtländer lenses that I bought, a Voigtländer Color Skopar Pancake II 1:2.5/35 mm and a Voigtländer Color Skopar Pancake II 1:4/21 mm, were decentered. So I sent them back (the 35 mm lens even twice) and eventually bought the equivalent Zeiss Biogon lenses, a Zeiss Biogon T* C 21mm f/4.5 and a Zeiss Biogon T* C 1:2.8/35 mm, at a much higher cost.

Here is the story of the two Voigtländer lenses that I bought initially. And here is my Zeiss Biogon T* C 21mm f/4.5 that replaced the Voigtländer 21 mm pancake lens:

Photos: Arrived on November 32, 2011 as a replacement: Zeiss Biogon T* C 21mm f/4.5 ZM (black) (31.5 mm equiv.)

The Zeiss 21 mm lens is a little bit slower (f/4.5 versus f/4), heavier, and much more expensive than the respective Voigtländer pancake lens.

On the M-mount expansion unit, this lens has an equivalent focal length of 31.5 mm and thus, is a bit less wider than a 28 mm lens - this may or may not be a problem for you.

Body with Lens Attached

Photo: Body with A12 M-mount expansion unit attached and Zeiss Biogon 21mm f/4.5 lens

Some Technical Data

Focal length	21 mm (31.5 mm equiv.)
Angle of view (35mm film)	90° diagonal
Maximum aperture	4.5
f-stop range	4.5-22
Number of iris blades	10
Number of lenses/groups	8/6
Shortest distance	0.5 m
Weight	210 g (190 g)
Length (w/wo cap)	56 mm (31 mm)
Maximum diameter	53 mm
Filter thread	46 mm
Lens hood	does not have one

Sample Images

Here are a few samples taken with the Zeiss Biogon 21mm f/4.5 lens (click the images to view the unprocessed original files in a new window):

Conclusions

Disclaimer: I am not a lens expert who sees marked differences between various Leica and/or other lenses. I can check for soft corners, find differences in color rendition, and, in rare cases, may discover a "3D look", but that's all. Please regard therefore my conclusions as the verdict of a "layman".