Mamiya 645 80mm f/2.8: Diaphragm Stuck Wide Open From Oil
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
This Mamiya 80mm f/2.8 lens for the 645 wins the contest this week for most oil on a set of diaphragm blades. The symptom that this produces is a diaphragm that is always wide open at f/2.8 so the lens is not that useful. After the blades are removed and cleaned, the complete inner lens barrel needs to be cleaned of oil contamination so that we don’t repeat this problem any time soon.
