Rangefinder calibration on Mamiya 7II

[Giovanna]

Can anyone point out where I can find accessible instructions on how to calibrate the rangefinder on the Mamiya 7?
Also, would the calibration be different between the 65, 80 and 150 (meaning: would I have to recalibrate if I were to switch lenses?)
Thanks to all those who can help

 

[brbo]

Emergency field rangefinder adjustment

 

[MTGseattle]

Is yours off enough that you are getting bad negatives as a result? I had a Mamiya 6 that was off only on the vertical axis and I used it as-is for a few years without issue.
It's a delicate mechanism, and the general opinion is if you're nervous about it or not really a "fix-it" type to not mess with it. Repair for them is getting difficult in the US and I have no idea what service/repair for these would be like in the UK. If you are careful, I see no reason why you can't adjust it yourself.

The rangefinder adjustment screw is hiding behind that small round cap on the upper rear of the camera body. about 20mm right of the viewfinder.

 

[L Gebhardt]

You should not need to recalibrate after changing lenses. I think it would make sense to calibrate with your longest lens since that will magnify errors and the 150mm is very hard to focus precisely wide open. I used similar instruments to the ones linked above. I also used a ground glass from a 6x6 camera held to the film guides with the back open to confirm the adjustment at close up distances after performing the adjustment at infinity. If you do check on a ground glass you can confirm with all your lenses.