[Leica] Jupiter-12 on Bessa R2: Real Data

[Martin Howard <mvhoward@mac.com>]

I couldn't find any definitive answers on the web, so I conducted a 
little experiment myself.  I wanted to see if I could fit and use the 
35mm f/2.8 Jupiter-12 lens on a Voigtlander Bessa R2.  I was using a 
Voigtlander 35mm/135mm LTM->M adapter at the time, and my results are 
as follows.

Provided the lens is racked to its closest focus, the lens will mount 
on the Bessa R2.  Contrary to a number of -- uninformed -- sources, the 
rear lens element of the lens does NOT foul the closest pair of shutter 
blades.  In fact, a cursory examination of the cameras innards, with 
the shutter open (set to B and hold down shutter release) will 
trivially show this.

The problem is that, while there is a cut-out for deep rear element in 
the top and bottom of the body, the Jupiter-12 is too deep still.  As a 
result, when focussing towards infinity, the large, rear, bulging lens 
element *will* come in contact with the camera body.  The end result of 
this, in turn, is that focussing at infinity is *not* possible.

Additionally, the rear lens element is set so far back, that it 
obstracts the light metering cell set in the top of the camera body.  
So, even if you limit your focussing to less than 4m (which is roughly 
where I started feeling resistance) you would not be able to use the in 
camera meter.

Please note: I have *not* tried this on the Bessa R, nor on the Bessa 
L, so I don't know whether this would or would not work on those 
cameras.

M.

- -- 
Martin Howard
mvhoward@mac.com

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