Mamiya 7 43mm Lens: Construction Differences and Special Tools
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
This Mamiya 7 43mm lens is having some service done to it and I thought I would point out some differences between it and the other Mamiya 7 lenses in construction.
First, because of the large rear element design, there is little space between it and the protective cowl. To remove the element a spanner wrench is used and although multi-purpose spanners are useful, in this case I use a Mamiya tool made just for this element removal because of the very tiny space between the glass and the notched retaining ring. Without this tool, it could be easy to damage the rear element with just a little bit of a slip. Photo two shows the tool and photo three shows it being used for element removal.
Also, because of the rear element design, most of the rangefinder system is located inside of the rear cowl as seen in photo four.
Photo five shows the rear element with the brass adjustment washer. In the background are the two gauge fixtures used for measuring the spacing between front and rear element groups. Although I did not have a reason to believe this spacing would be incorrect (no evidence of previous repair) I still check this as a matter of course.
