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

Mamiya-Sekor 360mm f/6.3 (RB67)

Mamiya · Mamiya RB67 · 1974

single source, unconfirmed

Also known as: Mamiya 360mm f/6.3 RB67 · Mamiya RB67 360mm f6.3 · Mamiya-Sekor 360mm f/6.3 · Mamiya-Sekor C 360mm f/6.3 · Mamiya Sekor C 360mm f6.3 · Mamiya 360 6.3 RB · セコール 360mm F6.3 · セコールC 360mm F6.3 · マミヤ RB67 360mm

Variants & identification

Variant Mount Years Serial ranges Production
Mamiya-Sekor 360mm f/6.3 (original, single-coated) · Seiko #1 mechanical leaf shutter, 1s–1/400 and T Mamiya RB67 — — —
Mamiya-Sekor C 360mm f/6.3 (multicoated) · Seiko #1 mechanical leaf shutter, 1s–1/400 and T Mamiya RB67 1974 — —
  1. Maker figures are from the RB67 Pro-S instruction book at butkus.org (8 elements in 5 groups, 14°, f/45, 77 mm, 1,230 g); closest distances and the two weights that separate the versions come from the RB67 Camera Guide (rb67.helluin.org) and Japanese Wikipedia, and Kamerastore's listing for the single-coated lens (1,260 g, 165 × 92 mm, 4.5 m) is a dealer's measurement. The book's weight matches the Camera Guide's figure for the original rather than for the C.
  2. The 1974 date is the Pro-S generation's: the 360 is not in the 1970 instruction book, and the copy of the Pro-S book consulted is a later printing that also lists the 37, 50 and 500 mm lenses, so no Mamiya document consulted dates either version of the 360. No last year and no list price has been found.
  3. The K/L 360mm f/6 L of the Pro-SD generation is a different lens with a different maximum aperture and is not a variant here; the RB67 Camera Guide could find no optical details for it and believes it was sold before the 350mm f/5.6 APO. Sellers' listings of it are excluded by the K/L terms in the listing filter.
How to tell them apart (expand)
  • The name ring sorts them: MAMIYA-SEKOR with a chrome front ring is the single-coated original, SEKOR C the multicoated lens; a K/L 360 is the later f/6 lens, not this one
  • Weight separates the two by the Camera Guide's figures, 1,230 g against 1,040 g, though the Pro-S book prints 1,230 g for its 360
  • Every version takes 77 mm screw-in filters, has its own screw-in hood and focuses on the body's bellows, which is why closest distances are quoted from the front rim
  • Neither version has an adapter ring: a Sekor or Sekor C goes on a Pro-SD or an RZ67 with a separate lens mounting ring, which Reznitsky's chart recommends

Mamiya-Sekor 360mm f/6.3 (original, single-coated):

  • Engraved MAMIYA-SEKOR 1:6.3 f=360mm with no C; chrome front ring; single coating (camera-wiki's original generation)
  • RB67 Camera Guide: 14°, 8 elements/5 groups, 77 mm, closest focus 4 m, 1,230 g, f/45; Kamerastore's listing gives 1,260 g, 165 × 92 mm and 4.5 m
  • Japanese Wikipedia lists セコール 360mmF6.3 as 5群8枚 with a 77 mm thread and no closest distance

Mamiya-Sekor C 360mm f/6.3 (multicoated):

  • C after Sekor; black barrel; multicoated (camera-wiki)
  • RB67 Pro-S instruction book: 8 elements in 5 groups, picture angle 14°, minimum aperture 45, 77 mm filter, screw-in hood, 43-6/16 oz (1,230 g)
  • RB67 Camera Guide: closest focus 3,460 mm, 1,040 g; Japanese Wikipedia gives 3.46 m from the front rim
  • Two-letter date-code sticker on the rear of the lens (Mamiya Repair)

Serial-range notes

two-letter sticker on the rear of the lens
Mamiya dated RB and RZ lenses with a two-letter code stuck to the back of the lens: the first letter is the year, the second the month, A = January. Year letters run A–J for 1971–1980 and A–T for 1981–2000, so the decade has to be read from the generation (Mamiya Repair). No serial-to-year table for the 360 has been published.

Specifications

Formula
8 elements in 5 groups (RB67 Pro-S instruction book, Japanese Wikipedia, camera-wiki)
Construction
8 elements / 5 groups
Aperture range
f/6.3–f/45
Shutter
Seiko #1 mechanical leaf shutter in both versions, 1s–1/400 and T, flash sync at all speeds (Pro-S instruction book). Focusing is by the body's bellows, so the lens has no helicoid.
Min. focus
3.46 m
Weight
1230 g
Filter
77 mm
Years manufactured
1974
Country
Japan
Coating
Single coating on the Mamiya-Sekor; multicoated on the Sekor C (camera-wiki)

What reviewers say

Optical formula — 8 elements in 5 groups (RB67 Pro-S instruction book, Japanese Wikipedia, camera-wiki)

No cross-section found: the RB67 Pro-S instruction book at butkus.org gives a specification block, extension-tube and depth-of-field tables without an optical diagram, the 1970 book does not list the lens, and no Mamiya data sheet for the 360 is online.

History

The 360mm f/6.3 was the long end of the RB67 system before the Pro-SD’s APO lenses: the 1970 instruction book stops at the 250, and the 360 appears in the Pro-S book with its own specification block, 8 elements in 5 groups, a picture angle of 14°, f/6.3 to f/45, a 77 mm filter thread, a screw-in hood reserved for it alone where the 127 to 250 share one, and 43-6/16 oz, or 1,230 g. Like every RB lens it has a Seiko #1 leaf shutter, 1 second to 1/400 with sync at every speed, and no helicoid; the body’s bellows do the focusing, which is why the closest distance, 3.46 m for the C by Japanese Wikipedia and the RB67 Camera Guide, is quoted from the front rim, and why the Pro-S book’s extension-tube table takes the 360 to 0.13× on tube No. 1. Mamiya’s bellows hood G-3 covers the 65 to 360 mm lenses and the Pro SD accessory page lists a soft pouch made for the 360 alone, a measure of its length.

Two versions carry the f/6.3 aperture. The single-coated Mamiya-Sekor has a chrome front ring and no C; camera-wiki puts it in the original generation, the Camera Guide gives it 4 m closest focus and 1,230 g, and Kamerastore’s listing measures 165 by 92 mm and 1,260 g. No source consulted says when it appeared beyond its absence from the 1970 book. The Sekor C is the multicoated lens of the Pro-S era, 3,460 mm and 1,040 g by the Camera Guide; the Pro-S book prints 1,230 g for its 360, which matches the original’s figure rather than the C’s, and the copy of that book online is a later printing that also lists the 37, 50 and 500, so it does not settle which lens it describes. The 360 stayed in the catalogue into the Pro-SD years, whose manual lists a hood for it, but Mamiya’s Pro SD lens page of 2011 to 2013 no longer carries it.

The K/L 360mm f/6 L of the Pro-SD generation is a separate lens with a different maximum aperture and is not treated as a version here; the Camera Guide could find no optical details for it and believes it was sold before the 350mm f/5.6 APO arrived, which is the lens that replaced the 360 at the top of the range. The RZ67 has its own Z 360mm f/6, a 6-element design by the Emulsive lens table, so an RZ owner’s opinion of “the 360” is not an opinion of this lens. Mounting is the usual Sekor rule: no adapter ring, and a separate lens mounting ring recommended by Reznitsky’s chart for a Sekor C on a Pro-SD or an RZ67, whose Pro IID brochure asks that RB lenses be inspected by a Mamiya service centre first; the pre-1978 lenses are listed as unusable on an RZ.

Reviews of the RB 360 itself are thin. Scott McClarin at Emulsive calls the Sekor C lenses exceptionally sharp and warns that older lenses show more chromatic aberration; Mark Foster at Japan Camera Hunter trusts every RB lens to be sharp and sees the C-versus-K/L argument as a division among owners; a reader on the Camera Guide’s page uses the C 360 handheld and still gets “very sharp results”; Pierre-gilles Lucain’s praise for the Z 360 on the RZ, “really incredible”, is for the other design. What to check when buying is what any RB lens needs: every shutter speed, the slow ones especially, the cocking action on and off the body, the diaphragm blades, and the front group for separation on the single-coated lens. Open questions: the first year of the original 360, the changeover to the C, the last year, the reason for the two weights, and any list price in yen or dollars, none having been found.

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 wanted — shot with a Mamiya-Sekor 360mm f/6.3 (RB67)? We'd love to feature it (with credit).

Live listings

Asking price, USD: a median of $140 across 9 fixed-price listings on 2026-09-21 (middle half $130–$160). First day tracked.

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

Show 2 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 250mm f/4.5 (RB67) · Mamiya K/L 350mm f/5.6 APO L (RB67) · Mamiya APO-L 500mm f/6 L (RB67) · Mamiya-Sekor 180mm f/4.5 (RB67)

Sources (15)

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.