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

Mamiya-Sekor Macro C 140mm f/4.5 (RB67)

Mamiya · Mamiya RB67 · 1974

single source, unconfirmed

Also known as: Mamiya RB67 140mm f/4.5 macro · Mamiya RB67 140mm f4.5 Macro · Mamiya-Sekor Macro C 140mm f/4.5 · Mamiya Sekor Macro C 140mm f4.5 RB67 · Mamiya K/L 140mm f/4.5 M/L-A · Mamiya KL 140mm f4.5 Macro L-A · Sekor C 140/4.5 Macro · マミヤ RB67 140mm マクロ · セコールマクロC 140mm F4.5 · マミヤマクロKL 140mm F4.5

Variants & identification

Variant Mount Years Serial ranges Production
Mamiya-Sekor Macro C 140mm f/4.5 (Sekor C generation, multicoated, 7 elements) · Seiko #1, T and 1s–1/400, M-X sync Mamiya RB67 1974–1990 — —
Mamiya K/L 140mm f/4.5 M/L-A Macro (1990, Pro-SD generation, 6 elements) · 6 elements in 4 groups with a floating element (Mamiya Pro SD lens page; Japanese Wikipedia) · Seiko #1, 1s–1/400, T and B, X sync Mamiya RB67 1990 — —
  1. Element and group counts, picture angles, minimum apertures, hoods and weights are from Mamiya's Interchangeable Lenses for Mamiya RB67 booklet (butkus.org) for the C lens and from Mamiya's own Pro SD lens page (archived at ianbfoto.com) for the K/L, confirmed by Mamiya's c. 1994 brochure. Closest-focus figures are from Japanese Wikipedia, which cites Mamiya's catalogues: only a from-the-rim figure (0.514 m) is given for the C lens, so the family's minimum focusing distance is the K/L's 0.759 m from the film.
  2. The C lens's own introduction year is not published in any source consulted: the C booklet is undated and camera-wiki dates only the generations. 1974 is the start of the Sekor C generation and should be read as a floor, not a launch date. The K/L's year is that of the RB67 Pro-SD (September 1990, Japanese Wikipedia); no discontinuation dates are published.
  3. The RB67 Camera Guide gives the C lens as 800 g against Mamiya's 880 g; only the maker's figure is carried. Whether the C lens's floating ring works as the K/L's does is stated only by that guide and a Flickr group thread, forum sources; Mamiya's C booklet does not describe it.
How to tell them apart (expand)
  • Two name rings for the f/4.5 macro: Mamiya-Sekor Macro C (C generation, 7 elements, 880 g) and Mamiya K/L 140mm f/4.5 M/L-A (1990, 6 elements, 870 g, with the removable 7 mm rear ring). Weight will not separate them; the ring and the name will
  • Both have a floating-element ring on the barrel with its own scale, set to the subject distance after focusing with the body's bellows; both take 77 mm filters and the screw-in round hood shared with the 127, 150, 180 and 250
  • On the Pro-SD's 61 mm mount the C lens wants the 7 mm adapter ring Mamiya recommends for light sealing; the K/L carries that ring and sheds it for a Pro or Pro-S
  • Seiko #1 leaf shutter on both, cocked by the body's lever with cocking pins that must be turned fully to the red marks before mounting; the K/L adds a B setting to the C lens's T

Mamiya-Sekor Macro C 140mm f/4.5 (Sekor C generation, multicoated, 7 elements):

  • Macro C after Sekor on the name ring; black barrel; a floating-element ring with its own scale on the barrel in addition to the aperture and shutter rings
  • Interchangeable Lenses for Mamiya RB67 booklet: 7 elements in 4 groups, picture angle 35°, minimum aperture 32, screw-in 77 mm hood, 31.0 oz (880 g); the booklet says the lens's specific instructions are packed with it
  • Japanese Wikipedia, citing Mamiya's catalogue: closest focus 0.514 m from the front rim

Mamiya K/L 140mm f/4.5 M/L-A Macro (1990, Pro-SD generation, 6 elements):

  • K/L on the barrel with the M/L-A suffix and no Sekor name; removable 7 mm adapter ring at the rear (Pro-SD manual)
  • Mamiya's Pro SD lens page: 6 elements in 4 groups, 35°, minimum aperture 32, closest focus 759 mm at 0.33x, 77 mm filter, screw-in hood, 90 × 97.2 mm, 870 g; adjustable flat-field correction by a built-in floating element, 1:1 with the extension tubes
  • Japanese Wikipedia, citing the Pro-SD catalogue: 4 groups 6 elements, closest focus 0.759 m, or 0.512 m from the front rim

Specifications

Formula
7 elements in 4 groups with a floating element (Sekor Macro C); 6 elements in 4 groups with a floating element (K/L 140mm f/4.5 M/L-A)
Construction
7 elements / 4 groups
Aperture range
f/4.5–f/32
Shutter
Seiko #1 leaf shutter in the lens on both versions: 1s–1/400 and T, cocked by the body's lever, flash sync at every speed (M-X selector on the Sekor C, X contact and a B setting on the K/L)
Min. focus
0.759 m
Weight
880 g
Filter
77 mm
Years manufactured
1974
Country
Japan
Coating
Multicoated on the Sekor Macro C; Mamiya multicoating on the K/L of 1990

What reviewers say

Optical formula — 7 elements in 4 groups with a floating element (Sekor Macro C); 6 elements in 4 groups with a floating element (K/L 140mm f/4.5 M/L-A)

History

The 140mm f/4.5 Macro is the Mamiya RB67’s flat-field lens, a long-normal for 6 × 7 that Mamiya’s literature makes the equivalent of 68 mm on 35 mm film and that spends most of its life doing ordinary work. It arrived in the Sekor C generation: Mamiya’s Interchangeable Lenses for Mamiya RB67 booklet lists the Macro 140mm f/4.5C with the fisheye and the soft-focus 150 as lenses whose specific instructions come in the box, gives 7 elements in 4 groups, a picture angle of 35 degrees, minimum aperture f/32, the screw-in 77 mm hood shared with the 90, 127, 150, 180 and 250, and 880 g, and prints its cross-section on the second page. Japanese Wikipedia, citing Mamiya’s catalogue, puts closest focus at 0.514 m from the front rim. The macro in the name is relative: on the body’s 46 mm bellows the lens reaches about one third life size, and life size needs Mamiya’s auto extension tubes, 45 mm for No. 1 and 82 mm for No. 2. What makes it a macro is the floating element, a third ring on the barrel with its own distance scale, set after focusing so that the field stays flat at the distance in use.

The K/L 140mm f/4.5 M/L-A of 1990 is a recomputation rather than a recoating. Mamiya’s own Pro SD lens page gives 6 elements in 4 groups against the C lens’s 7, the same 35 degrees and f/32, closest focus 759 mm at 0.33x, 90 × 97.2 mm and 870 g, and describes an adjustable flat-field correction by a built-in floating element for copy work down to 1:1 with the tubes; Japanese Wikipedia, from the Pro-SD catalogue, gives 0.759 m, or 0.512 m from the rim, so the working distance is unchanged. Mamiya’s c. 1994 brochure repeats the figures and says the K/L lenses are optically identical to the RZ series designs, whose 140 carries the same M/L-A suffix. The name ring does the sorting, because 10 g of weight will not: Mamiya-Sekor Macro C is the 7-element lens, Mamiya K/L 140mm f/4.5 M/L-A the 6-element one, and only the K/L has the removable 7 mm ring at the rear that seats it on the Pro-SD’s 61 mm mount and comes off for a Pro or Pro-S. A C lens on a Pro-SD wants that ring added. The C lens’s own launch year is not published, and the brochure’s system chart still lists a Macro C 140mm f/4.5 four years after the K/L, so the two overlapped.

The reviewers this catalogue indexes like it without arguing about it. Japan Camera Hunter’s system piece is built around a Sekor C 140mm f/4.5 macro, the one lens the author names owning; he reports the running argument over whether the C lenses trail the K/L, finds no shortcoming in his own beyond price and compatibility, and would trust every RB lens to be grotesquely sharp. Peter Chong on Deployant shoots the 140 on a Pro SD and finds it very sharp corner to corner at every working aperture, explains the floating element on the barrel and the 1:3 limit without tubes, and calls it excellent as a portrait lens. Rob Davie on Emulsive has not bought one yet and says it is the lens he would love, for the detail the RB’s negatives give to close-in work. Nobody found here has put the 7-element and 6-element lenses side by side on film; the Photrio thread that asks whether the RB and RZ 140s are the same optically could not be read from here. Casual Photophile, Ken Rockwell and Lomography are not consulted by this catalogue.

Buying is about the shutter, then the rings. The Seiko #1 lives in the lens, is cocked by the body, and after years unused will often hang at T or drag at the slow speeds; before mounting, the cocking pins on the barrel must be turned all the way to the red marks, and the booklet says a lens stored for a long time should have its shutter released. Turn the floating ring through its whole scale and confirm that it moves freely and that the image on the ground glass shifts as it turns, because a ring seized at infinity leaves the corners soft at every close distance the lens exists for. The instruction sheet is hard to find, as the Flickr thread on it complains, so a copy in the box is worth something. Confirm the 7 mm ring on a K/L is present and unscrews, and budget for the extension tubes if life size is the point. No launch price in yen or dollars for either version was found, no serial-number table exists, and no discontinuation dates are published.

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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 140mm f/4.5 (RB67)? We'd love to feature it (with credit).

Live listings

Asking price, USD: a median of $210 across 14 fixed-price listings on 2026-09-21 (middle half $170–$310). First day tracked.

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

Show 8 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 127mm f/3.8 (RB67) · Mamiya-Sekor SF C 150mm f/4 (RB67) · Mamiya-Sekor 180mm f/4.5 (RB67) · Mamiya-Sekor 90mm f/3.8 (RB67) · Mamiya-Sekor 250mm f/4.5 (RB67)

Sources (11)

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.