Mamiya 645 Super/Pro/ProTL: Damage From a Broken Mirror Stop
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
I have done a few posts about the Mamiya 645 Super/Pro/ProTL mirror stop replacement but feel the need to post again as I have been seeing many of these cameras come through the shop with broken stops that cause deeper issues.
In the second photo I show the mirror stop spring and the end of the broken mirror stop with the adjusting screw still attached. These are what can cause a larger issue than just a broken stop. When the mirror stop breaks, if you are lucky it stays in one place and the issue is incorrect focus. If you are not lucky, the spring will move to the back of the mirror box and get into the shutter. The third photo shows the shutter curtain with the rear of the camera removed and you can see how the spring or the tip of the mirror stop can fall into this mechanism and cause mischief (usually a locked up shutter). Worst case is if it gets further into the mechanism and force is applied to wind the film and further damage is done.
Please check the mirror stop on your camera before it damages the shutter!
Easiest way to check is focus on something at infinity and if you can’t quite get infinity to focus correctly, it is very likely your stop is broken.
