Mamiya 7 150mm Lens: Calibrating the Rangefinder Cam
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
Servicing a Mamiya 150mm lens for the Mamiya 7. After checking focus on the lens, next stop is checking rangefinder cam movement. Until the rangefinder cam on the lens is calibrated, there is no sense in adjusting the rangefinder on the body. Total movement of the cam on the 150mm lens is 2.1mm and tolerance at infinity is minus 0.005 mm to plus 0.015 mm. As you can see in the photo, this lens came in at minus 0.03mm so it needed an adjustment. Especially on a 150mm lens, I’d like things to be a bit close on rangefinder calibration.. Many of the 150mm lenses that I see need adjustment to work optimally.
