Mamiya 645 55mm f/2.8 Lens: Oily Diaphragm Blade Cleaning
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
Performing a typical diaphragm cleaning service on a Mamiya 55mm f/2.8 lens for 645. Not only do the blades need to be removed for cleaning, but the operating ring and also the mechanisms in the rear of the lens that control the diaphragm. These all usually get contaminated with oil. If you look closely at the second photo, you can see the oil residue on many of the parts. This is why I cringe when I read the Internet advice to “get a cotton bud and some lighter fluid” to clean the blades. That might work for a minute or two.
