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

Mamiya-Sekor C 80mm f/2.8 (645)

Mamiya · Mamiya 645 · 1975

single source, unconfirmed

Also known as: Mamiya-Sekor C 80mm f/2.8 · Mamiya Sekor C 80mm f2.8 · Mamiya-Sekor C 80mm f/2.8 N · Mamiya 645 80mm f/2.8 · Mamiya 645 80mm f2.8 N · Mamiya M645 80mm 2.8 · Sekor C 1:2.8 f=80mm · Mamiya A 80mm f/2.8 N/L · マミヤ セコールC 80mm F2.8 · マミヤ645 80mm F2.8 · セコールC 80mm F2.8 N

Variants & identification

Variant Mount Years Serial ranges Production
Mamiya-Sekor C 80mm f/2.8 (1975 original) Mamiya 645 1975 — —
Mamiya-Sekor C 80mm f/2.8 N Mamiya 645 1985 — —
Mamiya A 80mm f/2.8 N/L (leaf shutter) · Built-in leaf shutter with its own speed ring and PC socket, flash sync at every speed to 1/500 (Wikipedia; camera-wiki); cocked by hand, or automatically by the Power Drive Grip WG401 on the second-generation bodies Mamiya 645 — — —
  1. Element counts, closest focus, filter size, dimensions and weight for the C lens are from Mamiya's C-era lens brochure (cameramanuals.org); for the N and A N/L lenses from Mamiya's N-era 645 Interchangeable Lenses instruction sheet (Butkus library).
  2. The N lens's weight: Mamiya's own instruction sheet prints 235 g; Philip Hens's 2011 system list and the Wikipedia table derived from it give 220 g. The maker's figure is carried in the table.
  3. Aperture blade count (6) comes only from the Wikipedia lens table; no Mamiya document consulted gives it.
  4. Variant start years are the body generations they shipped with (C with the M645 in June 1975; N with the 645 Super in December 1985). No source consulted dates the A 80mm f/2.8 N/L or the end of C production, and old stock overlapped the new: Wikipedia says the 645 Super was sold with either C or N standard lenses.
How to tell them apart (expand)
  • C or N after the aperture on the name ring is the generation: plain C (1975, metal aperture ring), N (1985, plastic aperture ring, new coatings); A ... N/L is the leaf-shutter lens with its own speed ring
  • All three versions are 6 elements in 5 groups and take 58 mm filters, except the N/L, which takes 67 mm and focuses only to 0.8 m
  • The 80mm f/2.8 shares its screw-in hood with the 110mm f/2.8 (Mamiya-Sekor C instruction sheet)

Mamiya-Sekor C 80mm f/2.8 (1975 original):

  • Name ring reads Sekor C with no N after the aperture; metal aperture ring; the early lenses have a chrome ring on the focusing grip that later C lenses lost (Wikipedia)
  • Mamiya's C-era brochure: 6 elements in 5 groups, 47° angle of view, f/22 minimum, 0.7 m closest focus, 58 mm filter, 47 mm long, 70 mm diameter, 250 g
  • Rubberised diamond-pattern focusing ring turning 180° from infinity to 0.7 m; A/M lever on the left of the barrel for depth-of-field preview (Modern Photography, January 1976)

Mamiya-Sekor C 80mm f/2.8 N:

  • N after the aperture on the name ring; plastic aperture ring in place of the C lens's metal one (Wikipedia)
  • Same 6/5 optics, 0.7 m and 58 mm filter; Mamiya's N-era instruction sheet gives 43.5 mm long, 70 mm diameter and 235 g, so it is shorter and lighter than the 47 mm, 250 g original
  • Popular Photography (November 2000) describes the N barrels as polycarbonate over die-cast aluminium, with a raised plastic ridge carrying the mounting dot

Mamiya A 80mm f/2.8 N/L (leaf shutter):

  • Engraved A rather than C before the focal length, and N/L after the aperture; a shutter-speed ring and a cable-release socket on the barrel (camera-wiki)
  • Mamiya's N-era instruction sheet: 6 elements in 5 groups, 47°, f/22, 0.8 m closest focus (against 0.7 m for the plain lens), 67 mm filter, 61.5 mm long, 79.6 mm diameter, 460 g

Specifications

Formula
Modified Gauss (Planar type), 6 elements in 5 groups (Modern Photography, January 1976)
Construction
6 elements / 5 groups
Aperture range
f/2.8–f/22
Diaphragm blades
6
Min. focus
0.7 m
Dimensions
70 × 47 mm
Weight
250 g
Filter
58 mm
Years manufactured
1975
Country
Japan
Coating
Multicoated from the start: the C in Sekor C is Mamiya's multicoating mark; Modern Photography (1976) describes dark magenta and dark green reflections; the N lenses carry revised coatings (Wikipedia)
Original price
US$190 with hood (Modern Photography, January 1976); no Japanese price found (today $1,050)

What reviewers say

Optical Ratings

Aggregated from the reviews above — follow the links for the full picture.

Chromatic aberration
axial red fringe
Vignetting
gone by f/5.6
Flare & ghosting
low
Distortion
slight, both types

History

The 80mm f/2.8 is the lens the M645 was sold with when Mamiya revived the 6×4.5 format in a single-lens reflex in June 1975, and it stayed the kit lens of every manual-focus 645 body through the 645E of 2000. Modern Photography, reporting on the camera in September 1975, called it a Zeiss-Planar-inspired six-element design; its full test in January 1976 put the construction at six elements in five groups in a modified Gauss formula, measured the actual focal length at 80.5 mm, and priced the lens at $190 with its hood against $445 for the body. Mamiya’s own brochure gives 47° angle of view, f/22 minimum, 0.7 m closest focus, a 58 mm filter thread, 47 mm length and 250 g, which makes it the smallest and lightest lens in the C line apart from the 70mm E.

Three versions exist and the name ring sorts them. The original is engraved Sekor C with nothing after the aperture; the C is Mamiya’s mark for multicoating, and Modern Photography noted the dark magenta and dark green reflections of the new coating. The N of 1985 arrived with the 645 Super: Wikipedia describes the N lenses as a cosmetic redesign with a plastic aperture ring and revised coatings over the same optics, and Mamiya’s N-era instruction sheet gives the N lens as 43.5 mm long and 235 g, a little shorter and lighter than the original (Philip Hens’s list and the Wikipedia table say 220 g; the maker’s figure is used here). The third is the A 80mm f/2.8 N/L, a leaf-shutter lens with its own speed ring and PC socket, 0.8 m closest focus, 67 mm filter and 460 g, built because the focal-plane bodies sync flash only at 1/60 s. When it was introduced is not stated by any source consulted.

The reviewers agree more than they disagree. Modern Photography in 1976 found excellent centre resolution from wide open, corners that never dropped below excellent, ghosting below average and about one percent pincushion distortion, and concluded it was a very fine performer as a normal lens in the format; the one reservation was a red fringe on axis that persisted to f/5.6. Popular Photography’s November 2000 test of the N lens measured slight barrel distortion instead (0.55 percent), excellent centre sharpness at every stop, corners only good at f/2.8 to f/4 and excellent from f/11, and fall-off gone by f/5.6. Mike Eckman, shooting a C lens on an M645 forty years on, calls it as sharp as they come; Kikie Wilkins and Tim Dobbs, on Emulsive, treat it as a competent compact standard that they reach past mainly for the 45mm’s field of view.

When buying, the two plain versions differ only in barrel: check that the aperture ring clicks at every full stop, that the A/M lever on the left of the barrel moves the diaphragm, and that the metering coupler on the aperture ring is intact, since the metered prisms read the aperture through it. The N/L lens adds a leaf shutter that must be cocked by hand on first-generation bodies or without the WG401 grip, and its 0.8 m closest focus and 67 mm filter make it a different tool from the plain lens. A 645 AF 80mm f/2.8 D shares the focal length and mount name but is an autofocus lens for the 645AF bodies and does not belong on this page.

What remains open: the year Mamiya stopped making the C barrel and the year the N/L appeared; the N/L shutter’s speed range; the blade count, which only the Wikipedia table gives; and any Japanese list price.

Expand Collapse

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 taken with the Mamiya-Sekor C 80mm f/2.8 (645)
Mamiya 645 Super with the Sekor 80mm f/2.8 and AE finder FK402 (Mathias Heinel) — Mathias Heinel from Malmö, Sweden, via Wikimedia Commons (CC BY-SA 2.0)
Sample photo taken with the Mamiya-Sekor C 80mm f/2.8 (645)
Bridge over Big Rocky Run, Virginia: 645 Super, Mamiya-Sekor 80mm f/2.8, T-Max 400 (Tom Mills) — Tom Mills, via Wikimedia Commons (CC BY-SA 2.0)
Sample photo taken with the Mamiya-Sekor C 80mm f/2.8 (645)
Garden lattice, Walney Visitor Center: 645 Super, Mamiya-Sekor 80mm f/2.8, Acros II (Tom Mills) — Tom Mills, via Wikimedia Commons (CC BY-SA 2.0)

Sample photo wanted — shot with a Mamiya-Sekor C 80mm f/2.8 (645)? We'd love to feature it (with credit).

Live listings

Asking price, USD: a median of $250 across 45 fixed-price listings on 2026-09-19 (middle half $200–$340). First day tracked.

Asking prices from the listings scanned, not sales; junk-flagged rows and auction lots excluded; other currencies are not converted.

Show 118 more 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 2026-09-19. Links go to the shop or marketplace that carries the item.

Related: Mamiya-Sekor C 110mm f/2.8 (645) · Mamiya-Sekor C 150mm f/3.5 (645) · Mamiya-Sekor C 45mm f/2.8 (645) · Mamiya-Sekor C 55mm f/2.8 (645) · Mamiya-Sekor C 80mm f/1.9 (645)

Sources (16)

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.