rangefinder patch is not matching up at infinity

[Raid Amin]

When I today tried out the Komura 105 3.5 on a Canon P, I noticed that at the infinity setting the RF images do no coincide. When switching to a Canon 50/1.2 on the same camera, the infinity RF images coincide.

Does this directly imply that the Komura lens needs adjusting or could it be that it will work well on another camera, such as a Leica M6?

By the way, the lens looks beautiful. It seems to be very well made.

[Bill Salati]

Do you have any other LTM bodies to try it on? It could be the camera or the lens, though if you're happy with focus on the 50/1.2 I'd say it's the lens. In theory, focus should be identical on every camera body from the pre war Leicas to the M8 and that should include Canons from about 1947 on.

Dante Stella had some interesting things to say about Canon 135s on his site. May apply to other 135s also.

Peter Dechert made some comments in his book on Canon RFs that Canon initially assumed the Leica thread was 39mm diameter by 1mm pitch. They later realized that the thread pitch was 26 threads per inch! A small but crucial difference if you are machining to precise tolerances. Because of that, early postwar Canons are sometimes not compatible.

[Raid Amin]

Bill,
I tried the lens on two different Canon cameras today. The lens focused well at infinity with one Canon but was slightly off with the other. Then I used another lens on the camera that did not match well with the Komura. Here, the lens focused well at infinity.

I had both cameras checked and corrected for accurate focus last year.