Mamiya 645 55mm f/2.8 Lens: Oily Blades and Flange Distance
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
Repair on Mamiya 55mm f/2.8 lens for 645 plus some technical info. This lens came into the shop with the typical oily blades. After cleaning, the blades in photo four are ready to do their diaphragm duty again.
Some technical info you probably don’t need to know: The last photo shows the lens in a fixture on the auto-collimator getting its flange to film distance checked and adjusted. On the Mamiya 645, this distance is 63.00mm (+.05mm)(-.03mm). Each tick mark on the fixture is .01mm. This lens initially checked in at 62.96mm so a tiny bit of adjustment was needed. In reality, this amount of error would not show up in an image if the lens was stopped down but shooting wide open it could make a small difference in sharpness if not adjusted.
In a rare moment these days (due to being real busy with client repairs), I purchased this lens for repair and resale so if anyone is looking for a near perfect copy of this 55mm lens, please make contact.
