BM, the cost is: unscrewing the optics capsule, putting the shim in place, screwing the capsule back in. Pretty cheap.
Originally Posted by BMbikerider
The root of this problem is this: Leica rangefinders were made to work directly - that is without a cam, the RF follower rests directly on the rear of the helicoid which holds the optics capsule - with a 51.6mm lens, while Zeiss Contax RFs used a 52. 4mm lens. (I'm going on memory here, but these #s are in the ballpark if not spot-on)
Putting the longer lens such as a J-3 or J-8 (copies of prewar Zeiss Sonnars) on a Leica-standard body means the lens will be focussed farther away than the rangefinder indicates. I've researched this only in the context of the two Jupiter lenses, I do not know if the Industars (Tessars) have the same affliction. Shimming the optics capsule is easy, but it only shifts the error from near to far, where DOF renders it much less of an issue. The calculated thickness of the shim for a J-8 is .00447".
I just recieved a J-8 which I plan to use on a Canon RF, I have yet to check how the lens matches up to the camera. But - the build quality is not bad at all, it is not a gorgeously made lens but it is far from junk; my main quibble (which I was aware of before I bought it) is that the aperture has no click stops, a lack which I intend to correct if at all possible. Mine was made in 1975 and is black, at least for now.
Last edited by E. von Hoegh; 10-11-2013 at 09:58 AM. Click to view previous post history.