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Service Manual: (Insert link to manual here)

Full CLA: 6-7 hrs.
Enter relevant notes here
Spray and bake threads: +1 hrs.
Enter relevant notes here
Haze / separation in doublets
Do not offer to correct. Cost and risk is too high. Replacing with a donor lens/element is recommended.
PL/EF mount conversion
PL or EF mount conversion is available for most Sekor C primes that are in the original Mamiya 645 mount. Conversion not available for lenses with an integrated shutter system or the Mamiya RZ mount system.
Re-anodize exterior: 7-8 hrs + $50/part (typically 5-7 parts)
some focal lengths may have helical attached to rear housing, if so, additional lapping is required after anodizing. Sekor C lenses have plastic housings. Be careful offering anodizing!
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This section restricted to Duclos Staff users.

Focus Ring O.D.: 2.912“
Zoom Ring O.D.:
Iris Ring O.D.: 2.75” (see notes)
De-click Y/N: Yes
Additional Notes:
Additional Notes:Iris gear is possible but not generally recommended since the surface area is very slim, the gear will cover the stop numbers (unless a custom segmented gear is made and attached via screws into the iris ring) and the iris rings on some Mamiya-Sekor lenses, specifically the C N variants, is plastic, which can flex. Generally, iris rings on the C versions are aluminum, while the iris rings on the C N versions are plastic. The quickest way to distinguish between a C and a C N variant (besides, of course, looking at the engraved serial ring — the C will always be green, while the N will be white) is the texture of the rubber focus grip. If the grip has a diamond texture, it is a normal C version. If the grip has an elongated bar-type pattern, it is a newer C N version.

Mamiya Focal Reducer Project Synopsis (Failed): The goal of this test was to bring the Mamiya Sekor-C lens from 645>FF. While the focal reducer did indeed reduce the focal length, the optics in this particular model of reducer are designed for FF>S35. While we are technically able to achieve a proper image, the coverage doesn't quite resolve a proper Super 35mm image, and the part we would need to fabricate would look ridiculous. It sticks out so far a custom PL cap would need to be designed as well.

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