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.
Note: You can view and download the original files of the samples (for downloading use the browser's context menu).
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.
Photo: Body with A12 M-mount expansion unit attached and Zeiss Biogon 21mm f/4.5 lens
|Focal length||21 mm (31.5 mm equiv.)|
|Angle of view (35mm film)||90° diagonal|
|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|
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):
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".
As far as I can see, the results that my Zeiss Biogon T* C 21mm f/4.5 lens produces with the M-mount expansion unit are very pleasing.
For more links related to the Ricoh GXR M-mount expansion unit, see page M-Mount Links.