Mamiya C 80mm Lens: Shutter Lubrication, Less Is More
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
While servicing this Mamiya C 80mm lens I thought I would do a post on shutter lubrication although this would apply to most lubrication matters in camera and lenses.
What I am going to describe here is a matter of personal preference and I realize that technicians all have their ways of lubricating shutters. I will point out the reasons for my preferences.
The saying “less is more” applies to the amount of lubrication that I put into shutter mechanisms. The issues with over lubrication are: 1.) lubrication can attract dirt/dust/debris and 2.) Lubrication can migrate to places that it should not be 3.) Over lubrication can actually slow things down. Also, I have seen lots of lubrication used to cover up sins of not cleaning properly.
Photo two shows a Seiko shutter with the cocking ring removed. The ring has been lubricated with Mamiya “banana grease” and you can notice that it is barely visible. With exposure to 365nm UV light, photo three shows how the lubrication has covered all the contact surfaces of the cocking ring and the center support.
While I am writing of lubrication, now is a good time to mention how I feel about oiling speeds escapements in shutters. I feel the optimal amount of oil should be zero. I realize that many technicians do put a tiny bit of oil on the shafts but I feel that at best this will be benign and at worst will migrate onto the shutter blades. For a comparison, photo four shows a view of a high quality watch and the red jewel bearings are visible and you can notice the small oil cup above each jewel. Photo five shows the pinion shafts of the Seiko escapement (center and center left) and there are no oil cups, the factory installs these totally dry.
