Glass Bodies a variant-level encyclopedia of vintage lenses and cameras by iwillpat

Mamiya-Sekor Macro C 80mm f/4 (645)

Mamiya · Mamiya 645 · 1975

single source, unconfirmed

Also known as: Mamiya-Sekor Macro C 80mm f/4 · Mamiya Sekor Macro C 80mm f4 · Mamiya Sekor Macro C 80mm f/4 N · Mamiya 645 80mm f/4 Macro · Mamiya 645 Macro 80mm f4 N · Mamiya M645 80mm 4 Macro · Sekor Macro C 1:4 f=80mm · マミヤ セコール マクロC 80mm F4 · マミヤ645 マクロ 80mm F4 · セコールマクロC 80mm F4 N

Variants & identification

Variant Mount Years Serial ranges Production
Mamiya-Sekor Macro C 80mm f/4 (metal-barrel C lens) Mamiya 645 1975 — —
Mamiya-Sekor Macro C 80mm f/4 N Mamiya 645 1985 — —
  1. Construction (6 in 4), closest focus and filter thread are agreed by Japanese Wikipedia and the English Wikipedia table; the floating element system is Mamiya's own description in the Sekor C instruction sheet. Dimensions (75 × 79 mm), weight (585 g), the f/22 minimum and the five aperture blades come only from the English Wikipedia table, so the page carries the single-source flag.
  2. Closest focus: 0.36 m in Japanese Wikipedia, 0.37 m in the English table. The Japanese figure is carried; the difference is a rounding.
  3. Neither barrel is dated by any source consulted. The C year is the C line's start with the M645 (June 1975, Japanese Wikipedia); the N year is the 645 Super's (December 1985). camera-wiki files the C lens in its original list and the N in its newer list; the 645 Pro TL book of 1997 still lists the N.
  4. The Macro A 120mm f/4 M is a different lens, nine elements reaching 1:1 on its own helicoid; this 80 stops at 1:2 without the Auto Macro Spacer.
How to tell them apart (expand)
  • Macro before the C on the name ring and f/4 maximum aperture sort it from the 80mm f/2.8 and f/1.9 standard lenses; it is the only 645 80 with a 67 mm thread apart from the leaf-shutter 80mm f/2.8 N/L
  • C or N after the aperture is the barrel generation: metal aperture ring on the C, plastic on the N
  • Half life-size on its own; with the Auto Macro Spacer between lens and body, 1:2 to 1:1 with automatic diaphragm (Sekor C instruction sheet)

Mamiya-Sekor Macro C 80mm f/4 (metal-barrel C lens):

  • Name ring reads Mamiya-Sekor Macro C 80mm 1:4 with nothing after the aperture; metal aperture ring, as on the other C lenses (Wikipedia on the C and N barrels)
  • Focuses on its own helicoid from infinity to half life-size; the optional Auto Macro Spacer carries it from 1:2 to 1:1 (Mamiya's Sekor C instruction sheet)
  • 67 mm filter thread and no hood; 75 mm long, 79 mm across, 585 g (Wikipedia table)

Mamiya-Sekor Macro C 80mm f/4 N:

  • N after the aperture on the name ring; plastic aperture ring in place of the C lens's metal one (Wikipedia on the N barrels)
  • Same 6 elements in 4 groups, 0.36 m closest focus and 67 mm filter as the C lens (Japanese Wikipedia)
  • Listed as 'Macro 80mm f/4N' in the 645 Pro TL instruction book of 1997 and as 'C 80mm f4N macro' in camera-wiki's newer-lens list

Specifications

Formula
6 elements in 4 groups with a floating element system (Mamiya's Sekor C instruction sheet; Japanese Wikipedia 4群6枚; Wikipedia table)
Construction
6 elements / 4 groups
Aperture range
f/4–f/22
Diaphragm blades
5
Min. focus
0.36 m
Dimensions
79 × 75 mm
Weight
585 g
Filter
67 mm
Years manufactured
1975
Country
Japan
Coating
Multi-coated: Mamiya's Sekor C sheet says all the lenses for the M645 have been multi-coated, and the C in Sekor C is Mamiya's multicoating mark (Wikipedia); the N lenses carry revised coatings (Wikipedia)

What reviewers say

No reviews aggregated yet — this family is still in the research queue. Written one? We'd love to index it.

History

The Macro C 80mm f/4 is the close-focusing lens of Mamiya’s manual-focus 645 system, a six-element, four-group design with a floating element system that, in Mamiya’s own words in the Sekor C instruction sheet, automatically corrects close-distance aberration to hold resolution to the edges in close-ups and copying. On its own helicoid it runs from infinity to half life-size, with a closest focus of 0.36 m by Japanese Wikipedia; the optional Auto Macro Spacer fitted between lens and body takes it from 1:2 to life size with the automatic diaphragm intact. The Wikipedia table adds the figures Mamiya’s sheet prints only as an image: f/4 to f/22, five aperture blades, a 67 mm filter thread, no hood, 75 mm long by 79 mm across and 585 g. It is a 50 mm equivalent on 35mm film and, at f/4, a stop slower than the standard 80mm f/2.8 whose focal length it shares.

Two barrels exist and the optics do not change between them. The C lens has a metal aperture ring and nothing after the aperture on the name ring; camera-wiki lists it among the original C lenses, and no source consulted gives it a date of its own, so the year here is the C line’s start with the M645 in June 1975. The N lens, which Wikipedia describes as a cosmetic redesign with a plastic aperture ring and revised coatings over the same glass, shipped with the 645 Super generation of December 1985 and stayed in the line to the end: the 645 Pro TL instruction book of 1997 still lists ‘Macro 80mm f/4N’ beside the Macro 120mm f/4 M. The 120 is the other macro of the system and a different lens, nine elements reaching 1:1 without a spacer.

No published review of this lens was found by the searches made for this page; what surfaced were dealer listings, which repeat the specification and the 1:2-with-spacer arrangement, and nothing that tests it on film. What can be said from the documents is what it is for: a flat-field normal lens that doubles as a copying and close-up lens, which is why Mamiya gave it a floating group rather than a faster aperture.

When buying, work the helicoid through its long travel to the 1:2 stop and check that the floating group moves without play, confirm the A/M lever on the barrel opens and closes the diaphragm, and look for the metering coupler on the aperture ring, which the metered prisms read. The Auto Macro Spacer is sold separately and is the part most often missing from a kit; without it the lens stops at half life-size. What remains open: the launch year of either barrel, a list price in any currency, and any independent test.

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This history is AI-written, from the sources listed at the foot of the page. Where the record is silent it says so rather than filling the gap — but no human wrote these sentences.

Example photos

Sample photo wanted — shot with a Mamiya-Sekor Macro C 80mm f/4 (645)? We'd love to feature it (with credit).

Live listings

Buying from Yahoo! Auctions outside Japan. It is a domestic marketplace: sellers ship within Japan, and most will not register an overseas buyer. A proxy service bids on your behalf, receives the item and forwards it, for a fee and a wait. Buyee, Jauce and ZenMarket each accept a Yahoo auction number directly. Listed alphabetically for information — none is recommended over another, and none of these is an affiliate link.

Listings updated 2026-11-02. Links go to the shop or marketplace that carries the item.

Related: Mamiya Macro A 120mm f/4 M (645) · Mamiya-Sekor C 80mm f/2.8 (645) · Mamiya-Sekor C 80mm f/1.9 (645)

Sources (5)

Every page here is assembled from public sources, and the gaps are real ones. If you own this lens, know a serial number I'm missing, or can see where I have it wrong, tell me — corrections, serials and sample photos are all worth having.