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

Mamiya-Sekor C 35mm f/3.5 (645)

Mamiya · Mamiya 645 · 1981

single source, unconfirmed

Also known as: Mamiya-Sekor C 35mm f/3.5 · Mamiya Sekor C 35mm f3.5 · Mamiya-Sekor C 35mm f/3.5 N · Mamiya 645 35mm f/3.5 · Mamiya 645 35mm f3.5 N · Mamiya M645 35mm 3.5 · Sekor C 1:3.5 f=35mm · マミヤ セコールC 35mm F3.5 · マミヤ645 35mm F3.5 · セコールC 35mm F3.5 N

Variants & identification

Variant Mount Years Serial ranges Production
Mamiya-Sekor C 35mm f/3.5 Mamiya 645 — — —
Mamiya-Sekor C 35mm f/3.5 N Mamiya 645 1985 — —
  1. Element counts, angle of view, closest focus, filter size, dimensions and weight for the C lens are from Mamiya's C-era lens brochure (cameramanuals.org); for the N lens from Mamiya's N-era 645 Interchangeable Lenses instruction sheet (Butkus library). The two sets of figures are identical.
  2. The family year (1981) is the earliest dated document consulted, Mamiya's 1981 US brochure; the undated C-era brochure that predates the S lenses already lists the 35mm, so the true launch year is earlier and unsourced. The N year is the 645 Super's launch (December 1985).
  3. Aperture blade count (6) comes only from the Wikipedia lens table; no Mamiya document consulted gives it.
How to tell them apart (expand)
  • Two barrels on one nine-element formula: C with a metal aperture ring and no suffix, N with the suffix, a plastic aperture ring and revised coatings; the optical figures do not change
  • 77 mm filter thread and no hood: Mamiya's brochures say the 35mm 'does not require a lens hood' and none was sold for it
  • A/M lever on the side of the barrel and a meter coupling prong beside the aperture ring, like every manual-focus 645 lens (slrlensreview)

Mamiya-Sekor C 35mm f/3.5:

  • Name ring reads Sekor C with nothing after the aperture; metal aperture ring (Wikipedia on the C and N cosmetics)
  • Mamiya's C-era brochure: 9 elements in 7 groups, 90°, f/22, 0.45 m, 77 mm filter, no hood needed, 61.5 mm long, 80 mm diameter, 445 g

Mamiya-Sekor C 35mm f/3.5 N:

  • N after the aperture on the name ring; plastic aperture ring and rubberised focusing ring (Wikipedia; slrlensreview)
  • Mamiya's N-era instruction sheet: 9 elements in 7 groups, 90°, f/22, 45 cm, 0.11×, 77 mm filter, no hood, 61.5 × 80 mm, 445 g; the same figures as the C lens

Specifications

Formula
Retrofocus wide-angle with a floating element group, 9 elements in 7 groups (Mamiya's C-era lens brochure; N-era 645 Interchangeable Lenses sheet)
Construction
9 elements / 7 groups
Aperture range
f/3.5–f/22
Diaphragm blades
6
Min. focus
0.45 m
Dimensions
80 × 61.5 mm
Weight
445 g
Filter
77 mm
Years manufactured
1981
Country
Japan
Coating
Multicoated: the C in Sekor C is Mamiya's multicoating mark; the N lens carries revised coatings (Wikipedia; slrlensreview)

What reviewers say

Optical Ratings

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

Vignetting
low
Flare & ghosting
no hood, flares

History

The 35mm f/3.5 is the widest rectilinear lens of the manual-focus Mamiya 645 system, a 22 mm equivalent with a 90° angle of view, and the only wide in the line that Mamiya sold without a hood of any kind. It is a nine-element, seven-group retrofocus design that shares with the 45mm f/2.8 a floating system, in which some of the elements move as the lens is focused so that edge resolution holds at the 0.45 m closest distance. Mamiya’s C-era brochure gives it as 61.5 mm long, 80 mm across and 445 g, with a 77 mm filter thread. It was not among the seven lenses announced with the M645 in 1975 and 1976; it is in the undated C-era brochure that also lists the 80mm f/1.9, and in the 1981 US brochure, and no source consulted says in which year it arrived.

Two barrels carry the same glass. The original Sekor C has a metal aperture ring and no suffix. The N of December 1985, launched with the 645 Super, adds the N after the aperture, a plastic aperture ring, a rubberised focusing ring and revised coatings, and Mamiya’s N-era instruction sheet repeats the C lens’s figures to the gram (9/7, 90°, 45 cm, 77 mm, 61.5 by 80 mm, 445 g). Unlike the 45 and the 55, the 35 had no S version. The autofocus 35mm f/3.5 for the 645AF bodies is a different lens and is not covered here.

Reviewers agree on the centre and disagree on the rest. slrlensreview, testing an older non-N lens on Canon bodies, found the centre very good at every aperture, the borders average at f/3.5 and f/4 and only decent from f/5.6 to f/11, with visible lateral colour at the edges and very little vignetting, and concluded that the gap between centre and border never closes. atmtx, using an N lens on a GFX 50R for architecture, calls it adequately sharp with good corners at f/16 on a tripod, but reports barrel distortion at the edges that generic corrections do not fully remove, and hexagonal flare and green smudges when a bright light is near the frame. Both note the outstanding all-metal build and the pleasant damped focusing.

Flare is the thing to plan for, since no hood was ever offered; a deep 77 mm screw-in hood for a 22 mm equivalent will vignette, so most users shade the lens by hand. When buying, check that the A/M lever stops the diaphragm down and returns it, that the meter coupling prong beside the aperture ring is intact, and that the focusing ring turns smoothly over its whole range, because the floating group rides on it. Listings that quote 445 g and 77 mm describe either version; only the suffix on the name ring and the material of the aperture ring separate the C from the N.

What remains open: the year the C lens appeared, the end of C and N production, any list price, and the blade count, which only the Wikipedia table gives.

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 35mm f/3.5 (645)
Mamiya-Sekor C 35mm f/3.5 N, the widest rectilinear lens of the 645 system (Jacopo188) — Jacopo188, via Wikimedia Commons (CC BY-SA 3.0)
Sample photo taken with the Mamiya-Sekor C 35mm f/3.5 (645)
Victoria Harbour, Melbourne Docklands: 645 Pro TL, Sekor 35mm f/3.5 N, Tri-X, red filter and polariser (Jes) — Jes (mugley), via Wikimedia Commons (CC BY-SA 2.0)
Sample photo taken with the Mamiya-Sekor C 35mm f/3.5 (645)
Alley in the Melbourne CBD, long exposure: 645 Pro TL, Sekor 35mm f/3.5 N, Neopan Acros 100 (Jes) — Jes (mugley), via Wikimedia Commons (CC BY-SA 2.0)

Sample photo wanted — shot with a Mamiya-Sekor C 35mm f/3.5 (645)? We'd love to feature it (with credit).

Live listings

Asking price, USD: a median of $590 across 35 fixed-price listings on 2026-09-21 (middle half $520–$660). First day tracked.

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

Show 74 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 2026-09-21. Links go to the shop or marketplace that carries the item.

Related: Mamiya-Sekor Fisheye ULD C 24mm f/4 (645) · Mamiya-Sekor Shift C 50mm f/4 (645) · Mamiya-Sekor C 70mm f/2.8 Leaf Shutter (645) · Mamiya Macro A 120mm f/4 M (645)

Sources (12)

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.