Manufacturer | Mamiya-Sekor |
Series | 645 |
Model | A APO Macro |
Focal Length | 120mm |
Max Aperture | f/4 |
Min Aperture | f/32 |
Format | 645 |
Image Circle | - |
Minimum Focus | 1.32' / 0.402m |
Focus Rotation | - |
Iris Blades | 9 |
Optical Design | 9 / 8 |
Squeeze | n/a |
Front Diameter | 2.75“ |
Filter Thread | 67mm |
Focus/Zoom Rod | n/a |
Native Mount | Mamiya 645 |
Data Protocol | n/a |
Length | 4.4 in. |
Weight | 745g |
Body Telescope | - |
Body Material | - |
Focus Drive | Manual |
Iris Drive | Manual |
Zoom Drive | n/a |
Country of Origin: Japan
Release Date:
Launch Price:
Design Revisions:
This section restricted to Duclos Staff users.
Service Manual: (Insert link to manual here)
Full CLA: 5-6 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: 6-7 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!
…end of Staff section
This section restricted to Duclos Staff users.
Focus Ring O.D.: 3.035”
Zoom Ring O.D.:
Iris Ring O.D.: 2.95“ (see notes)
De-click Y/N: Yes
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.
…end of Staff section