Canon 7 lens mount question

[Dave Wilkinson]

The lens mount flange on my recently aquired 7 is somewhat raised from the body, to accomodate the bayonet that is used for the 0.95 'dream' - I'm wondering if the film plane-to-flange distance is still the same as Leica etc. ( 28.8mm, I believe ? ).
The reason I ask, is - I just screwed the f1.2, 50mm Canon lens onto my Fed 2, and when I focus on an object at around nine feet away,- the lens scale reads around fifteen or sixteen feet. The body has a half used film in, or I would get my depth-gauge in, and measure. I did take a few shots with the 7 and a Jupiter 8 that usually lives on the Fed, and they seem ok,-albeit at around f8!

BTW, I have mixed feelings about the 50mm f1.2,- first impressions where to get rid quickly!, but on revisiting the scans, I quite like some of the renderings, (Portra VC) - and intent to give a fair trial with some different stock, and B+W, before passing it on! Anyone use this lens-on a regular basis ?-what's your honest opinion?

Regards, Dave 😱

 

[John Shriver]

The 7 is fully in conformance with the Leica M standard. Standard 28.80mm film-flange distance, standard rangefinder action.

Sounds like the focusing helical on your 50/1.2 is on the wrong start. When you focus it to infinity, the RF cam should stick out 7.5mm (as exactly as you can measure) from the mating face of the lens mount.

Also, just in case you missed the obvious -- some Canon RF lenses were made with focusing scales only in meters.

 

[Dave Wilkinson]

Thanks, John-it does measure exactly 7.5mm, I think the difference I'm seeing must be down to a different helix pitch in the two lenses. Quite an interesting and informative discusion going on, right now,-re this optic! I can't wait to give mine some more trials!

Regards Dave.