Canon 2/100 focusing question

[vmk]

Hello everyone, I have a very clean and smooth 2/100 lens that, according to Peter Kitchingman's site, appears to be a Type 2 (serial number 15xxx). Do you know if its focusing mechanism can be finely adjusted and how? On professionally adjusted rangefinder camera bodies (M3, M2) what is the importance of the screwmount to bayonet adapter if one wants acceptably accurate focus at 1m and f/2 or f/2,8? For example, using an original Leitz 9cm adapter I can't even get the moon to align properly at infinity, let alone close focus. It does better with a (thinner?) cheap Chinese 35/135 ring (though still not spot on) but the "correct" 90mm framelines are not brought up. Any ideas?

 

[Erik L]

its almost always the camera thats out of adjustment with these. i would be very careful about anything, try another body perhaps

 

[peterm1]

i have had this issue with both a canon 85mm f1.8 and a 135mm f4. I too would like to know what to do.

 

[John Shriver]

Remove the M adapter. Focus the lens to infinity. Measure how far back the RF cam protrudes from the flat mating surface of the lens mount. If it is not exactly 7.5mm, the lens is probably put together wrong. (One of the helicals on the wrong start.)

The M adapter should be exactly 1.0mm thick.

Also, collimation of the lens must also be checked.

Send it to a pro, it will come back focusing accurately.

 

[vmk]

Thank you for your input. Would you like to suggest one or more repair persons with experience in Canon RF lenses?

 

[John Shriver]

DAG Camera, Sherry Krauter (Golden Touch).

 

[zeitz]

I like Focal Point in Colorado. focalpointlens.com But there is nothing unique about Canon RF lenses. Any shop with Leica experience can repair the lens.