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

Mamiya-Sekor 50mm f/6.3 (Press)

Mamiya · Mamiya Press · 1967

single source, unconfirmed

Also known as: Mamiya Press 50mm f/6.3 · Mamiya Press 50mm f6.3 · Mamiya-Sekor 50mm f/6.3 · Mamiya Sekor 50mm f6.3 Universal · Mamiya Universal 50mm f6.3 · Mamiya Super 23 50mm f6.3 · Sekor 50/6.3 · マミヤプレス 50mm · マミヤ セコール 50mm F6.3 · セコール 50mm F6.3

Variants & identification

Variant Mount Years Serial ranges Production
Mamiya-Sekor 50mm f/6.3 (black barrel, time-lock shutter) · Seikosha-S #0 (Seiko #0 in the later manuals), B and 1s–1/500, M-X sync; time lock by pushing and turning the release button at B Mamiya Press 1967 — —
  1. Element and group counts, picture angles, minimum aperture, filter size, hood type and shutter-arresting method are from Mamiya's own tables: the Super 23 manual (p.51), the 1969 Universal manual (p.18), the Universal Lenses booklet and the later Universal manual (p.46). The angle of view is 89°30' on 6×9 and 81°40' on 6×7 (the Super 23 table prints 81°38').
  2. Closest focus of 1.0 m is the first column of the Super 23 manual's metric depth-of-field table for the 50 and the figure Japanese Wikipedia gives; English Wikipedia's 3.3 ft agrees. No maker document states it as a specification.
  3. Weight of 610 g is English Wikipedia's and camera-wiki's figure; no Mamiya document consulted gives a weight for the 50. Kamerastore's listing says 611 g.
  4. Year: the 50 is not in the Press Standard manual, which lists the 65 as the system's only wide angle, and is in the Super 23 manual of 1967. No source gives a launch date, so 1967 is the earliest documented year and the lens may be older.
  5. The Super 23 manual calls the shutter Seikosha-S #0, the 1969 Universal manual Seikosha #0 and the later Universal manual Seiko #0; camera-wiki says the chrome lenses have the Seikosha-S and the later ones the Seiko #0. The 50 exists only as a black lens.
How to tell them apart (expand)
  • One version: black barrel, 72 mm filter thread, clamp-on hood, Biogon-type 8-element glass with a deeply curved front element
  • The shutter is held open for ground-glass focusing by the time lock, not by a lever: set B, cock, push the release button in and turn it clockwise (Universal Lenses booklet). Every other Press lens uses a time lever or a press-focus lever
  • Rangefinder coupled; framed with its own optical finder on the accessory shoe, which has a knob at the back for parallax (Universal Lenses booklet p.5)
  • Black type in Mamiya's tables: black-finished scale ring, side-reading shutter speed dial

Mamiya-Sekor 50mm f/6.3 (black barrel, time-lock shutter):

  • Black-finished barrel only: the Universal manuals list the 50 as a black type with no chrome version (double asterisk in the 1969 table, Black in the later one)
  • Bulbous front element behind a 72 mm clamp-on hood; shutter release button on the barrel that locks open when pushed in and turned clockwise at B (Universal Lenses booklet p.2)
  • Engraved Mamiya-Sekor 1:6.3 f=50mm; sold with a separate optical finder for the accessory shoe with a parallax knob at its back

Specifications

Formula
8 elements in 5 groups, symmetrical Biogon type (Super 23 and Universal manuals for the counts; English Wikipedia and camera-wiki for the type)
Construction
8 elements / 5 groups
Aperture range
f/6.3–f/32
Shutter
Seikosha-S #0 leaf shutter in the lens (Seiko #0 in the later Universal manual): B and 1s–1/500, cocked by a lever on the barrel, M-X flash sync at every speed; time lock (push and turn the release at B) holds the blades open for the focusing screen
Min. focus
1 m
Weight
610 g
Filter
72 mm
Years manufactured
1967
Country
Japan
Coating
Single-coated (Camera Reflections; Photo Thinking says the same of the Press lenses generally)

What reviewers say

Optical formula — 8 elements in 5 groups, symmetrical Biogon type (Super 23 and Universal manuals for the counts; English Wikipedia and camera-wiki for the type)

History

The 50mm f/6.3 is the widest lens of the Mamiya Press system and the one with the most glass in it: Mamiya’s tables give 8 elements in 5 groups, and the cross-section printed in the Super 23 manual and the Universal booklets shows a symmetrical wide angle with a deeply curved front element, which English Wikipedia and camera-wiki call a Biogon type. On 6×9 it covers 89°30’, on 6×7 81°40’, which is roughly a 21mm on 35mm film. The aperture runs to f/32, the filter thread is 72 mm with a clamp-on hood, and the whole lens weighs 610 g by the Wikipedia figure, since no Mamiya document consulted gives a weight. Closest focus is 1.0 m, the first column of the Super 23 manual’s metric depth-of-field table and the figure Japanese Wikipedia prints.

There is one version. Mamiya’s tables mark the 50 as a black-type lens only, with the black scale ring and side-reading speed dial, where the 65, 90, 100 and 150 also came chrome-plated. Its shutter differs from the rest of the range in one detail: to hold the blades open for the ground glass there is no time lever and no press-focus lever, but a time lock, which the Universal Lenses booklet describes as setting B, cocking, then pushing the release button in and turning it clockwise. The shutter itself is the same Seikosha-S #0 as the other lenses, B and 1 to 1/500 second with M and X sync at every speed, cocked by a lever on the barrel. The lens couples to the rangefinder; framing is by a separate optical finder on the accessory shoe, with a knob at its back to set the parallax for the focused distance.

Dating it is a matter of which manual lists it. The Press Standard manual of the mid-1960s knows one wide angle, the 65; the Super 23 manual of 1967 has the 50 in its table, and it stays through both Universal manuals. No source gives a launch date, so 1967 is the earliest year that can be documented and the lens may be older. The shutter name changes across the same documents, Seikosha-S #0 in the Super 23 manual, Seikosha #0 in the 1969 Universal manual and Seiko #0 in the later one, which is the rebranding of the shutter maker and not a change to the lens.

The reviewers agree on the one thing to watch. Kikie Wilkins on Emulsive shot the 50 for street work, likes its character, and warns that the large protruding front element catches stray light so that flare needs care even with the hood fitted. Greg at Camera Reflections says the same of the single coating and the bulbous front, recommends the hood, calls the lens slow but right for landscapes with low distortion, and finds the push-and-twist time lock fiddlier than the levers on the other lenses. Andrew Welsh at Shoot It With Film lists it as the rare lens of the system. Nobody consulted has measured it against the 65 or the 75 on film.

When buying, check that the lens comes with its finder, which is specific to the 50 and hard to find separately, and that the hood is there, because the lens needs it. Run the shutter through its speeds and try the time lock, which should hold the blades open and release cleanly when the button is turned back. Look at the front element under a light for cleaning marks, since it stands proud of the barrel, and for haze in the rear group. No list price in yen or dollars was found for the 50, no production figures, and no serial-number scheme; the weight is Wikipedia’s, not Mamiya’s.

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 50mm f/6.3 (Press)
Mamiya-Sekor 50mm f/6.3 with its optical finder and clamp-on hood — Zebrio (Brian Scott Peterson), via Wikimedia Commons (CC BY-SA 2.0)
Sample photo taken with the Mamiya-Sekor 50mm f/6.3 (Press)
The 50mm f/6.3 and its finder — Zebrio, via Wikimedia Commons (CC BY-SA 2.0)

Sample photo wanted — shot with a Mamiya-Sekor 50mm f/6.3 (Press)? We'd love to feature it (with credit).

Live listings

Asking price, USD: a median of $420 across 9 fixed-price listings on 2026-09-21 (middle half $380–$500). First day tracked.

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

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 65mm f/6.3 (Press) · Mamiya-Sekor 75mm f/5.6 (Press) · Mamiya-Sekor 90mm f/3.5 (Press) · Mamiya-Sekor 100mm f/2.8 (Press) · Mamiya-Sekor 100mm f/3.5 (Press) · Mamiya-Sekor 127mm f/4.7 (Press) · Mamiya-Sekor 150mm f/5.6 (Press) · Mamiya-Sekor 250mm f/5 (Press)

Sources (14)

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.