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

Mamiya-Sekor 250mm f/6.3 (C-series TLR)

Mamiya · Mamiya TLR · 1967

Also known as: Mamiya-Sekor 250mm f/6.3 · Mamiya Sekor 250mm f6.3 TLR · Mamiya 250mm f/6.3 blue dot · Mamiya-Sekor 1:6.3 f=250mm · Mamiya C330 250mm f/6.3 · Mamiya C220 250mm lens · Sekor 250/6.3 TLR · マミヤ セコール 250mm F6.3 · マミヤ C330 250mm · マミヤ 二眼 250mm F6.3 · ブルードット 250mm

Variants & identification

Variant Mount Years Serial ranges Production
Mamiya-Sekor 250mm f/6.3, black Seiko shutter, no aperture click-stops · Seiko, 1s–1/500 and B, M/X sync; cocked by hand on every body, the C33/C330 auto-cocking included Mamiya TLR (manual cocking on every body) 1967–1980 — —
Mamiya-Sekor 250mm f/6.3, Blue Dot (click-stopped aperture, later Seiko shutter) · Seiko (later type with raised-tip leaf), 1s–1/500 and B, M/X sync; cocked by hand on every body Mamiya TLR (manual cocking on every body) 1980–1994 — —
  1. Optical construction, picture angle, minimum aperture, filter and hood diameters, closest focus, reproduction ratio, weight and sync are from Graham Patterson's Mamiya TLR System Summary (June 2015 release), which compiles Mamiya's literature: 6/4, 18°, f/64, 49 mm, 50 mm hood, 205 cm, 31.1 cm field at 1:6.6, 645 g. English Wikipedia gives 630 g, 205.1 cm and 31.1 cm; Japanese Wikipedia 4群6枚, 2.05 m and φ49. Patterson notes that his weights may include caps; the two figures are both given here and the lower one used.
  2. The 1967 first year is a catalogue citation of 30 March 1967 that Patterson found; he says actual availability is unknown, and his chronology table starts the 250 in 1967 as inferred. The split into a plain black and a blue dot version rests on his general dating of click-stops and the blue insert 'from around 1980' and on his code notes for the 250, not on a 250-specific record; the C330s ended January 1994.
  3. No launch price in any currency was found.
How to tell them apart (expand)
  • Only ever a black Seiko lens: any chrome-bezel 250 offered as a C-series lens is something else
  • The one C-series lens that never auto-cocks: the shutter lever must be pushed by hand before each frame on a C33, C330, C330f or C330s as on a C220 (Patterson, Wikipedia, Williams, Japanese Wikipedia)
  • The 49 mm thread and the square flap-top hood are shared with the 55, 65 and 180; the 180 and 250 use the same hood (Patterson, 2.2)
  • Chrome keeper rings with internal ribs in the 49 mm thread are original equipment, not a damaged filter; Patterson's own 250 is photographed with them mounted
  • Sports-finder mask aperture for the 250 measures 15.5 mm; the C33 and later side dial has a combined 180/250 setting; earlier bodies needed a retrofit scale (Patterson, 5.1 and 6.4)
  • Not the RB67, RZ67 or 645 250s, nor the Press/Universal 250mm f/5: those are different lenses on different mounts

Mamiya-Sekor 250mm f/6.3, black Seiko shutter, no aperture click-stops:

  • Black series only: no chrome 250 exists (Patterson; English Wikipedia; Williams Photographic)
  • All-black Seiko shutter; speed and aperture scales read against a common index on the left, wide knurled speed ring, aperture knob on the right (Patterson, 4.0)
  • 49 mm filter thread, originally with chrome 'keeper' rings whose internal ribs are mistaken for a filter thread; 50 mm square flap-top hood shared with the 180 (Patterson, 4.0, 4.10, 2.2)
  • Closest focus 205 cm at 1:6.6; 645 g by Patterson, 630 g by Wikipedia; f/6.3 to f/64
  • No click-stops; millimetre engraving on 1970s lenses (Patterson, 4.0)

Mamiya-Sekor 250mm f/6.3, Blue Dot (click-stopped aperture, later Seiko shutter):

  • Blue insert in the tip of the shutter cocking lever, Patterson's mark of the newer shutter whose raised leaf tip resists the blades locking as they close (2.5)
  • Aperture click-stops at the full stops, from around 1980 (Patterson, 4.0)
  • Same optics, 49 mm filters, 205 cm and weight as the earlier lens

Serial-range notes

213xx – 218xx
Code IF; the lowest 250 serials Patterson tabulates.
46xxx
Code CI. Patterson also records CG as a 'middle' (1970s) lens, HE as one without the blue shutter insert, and DH, JF and HC unexamined. Mamiya has no serial date table and the letter series restarts per item, so these are his readings rather than factory data.

Specifications

Formula
6 elements in 4 groups, telephoto (Patterson; Japanese Wikipedia 4群6枚); type not named by Mamiya
Construction
6 elements / 4 groups
Aperture range
f/6.3–f/64
Shutter
Seiko leaf shutter in the taking lens, 1s–1/500 and B, M and X sync, flash at every speed; manual cocking on every body, the auto-cocking C33 and C330 series included
Min. focus
2.05 m
Weight
630 g
Filter
49 mm
Years manufactured
1967–1994
Country
Japan
Coating
Single-coated (Patterson, 2.4); he does not name the 250 among the late black lenses that may be multi-coated

What reviewers say

History

The 250mm f/6.3 is the longest lens of Mamiya’s interchangeable-lens twin-lens reflexes and the last focal length added to the line, an 18° telephoto that Anton McCloud calls the 250mm behemoth and that Mamiya sold only in the black Seiko-shutter series. Graham Patterson’s system summary, which compiles Mamiya’s literature, gives 6 elements in 4 groups in a telephoto layout, f/6.3 to f/64, a 49 mm filter thread with chrome keeper rings, the 50 mm square flap-top hood it shares with the 180, and a closest focus of 205 cm at which the bellows put a 31.1 cm square on the film at 1:6.6. He records 645 g with the caveat that his weights may include caps; English Wikipedia gives 630 g; Japanese Wikipedia agrees on 4群6枚, 2.05 m and φ49. Mamiya never named the design type in anything consulted.

There is one optical version and one shutter family. Patterson found the 250 and the 55 cited in an American distributor’s catalogue dated 30 March 1967, alongside the C22 and C33, but says actual availability is unknown; his chronology table starts the lens in 1967 as an inference, and the black series proper arrived with the C220 of 1968 and the C330 of 1969. What sets the 250 apart from every other black lens is that it never auto-cocks: the C33, C330, C330f and C330s cock the other lenses through the wind, but the 250’s shutter lever has to be pushed by hand before each frame on those bodies as on a C220, which Patterson, both Wikipedias and Williams Photographic all record. Within the black lenses Patterson sorts early, middle and late by engraving and click-stops, millimetres without click-stops through the 1970s, then click-stops at the full stops from about 1980, usually with a blue insert in the cocking lever that marks a newer shutter with a raised leaf tip. He records no 250-specific change, but his code table notes one 250 without the blue insert and another as a middle lens, so the two forms exist for this focal length as for the others; the split here rests on that general dating. The C33 and later side dial has a combined 180/250 setting; C3 and C22 bodies needed a retrofit scale.

Thomas Eisl is the one reviewer to have used it and written about it: perfect sharpness when stopped down, great bokeh, a pleasure to use, the only lens besides the 180 Super that he singles out in a system whose lenses he otherwise rates uniformly good. Marius Constantin’s buying guide places it as the long telephoto for specialist use and distant subjects; McCloud names it the far end of an excellent range. No test with figures exists, and the lens is scarce enough that nobody has compared examples.

Buying one is about the shutter and the handling. Set 1 second and listen, then fire at every speed, and cock it by hand before each test, which is how it will be used; Mamiya America told Patterson in 1999 that some parts for the early Seiko shutters were exhausted. Do not take the ribbed keeper rings in the 49 mm thread for a damaged filter, and check that thread for dents, the commonest fault Patterson records. At 630 g or more the pair is the heaviest in the line, so a wobble on the board matters, and Eisl warns that some lenses sit badly and soften the image; the sports-finder mask, the square hood and both keeper rings are the parts most often missing. Patterson’s rule of thumb for vibration gives the 250 a 2.5 mm tolerance, which argues for a tripod and the cable release. Serial numbers date nothing, since Mamiya has no table; the gold two-letter sticker, if it survives, is the only period clue.

What remains open: whether the lens actually shipped in 1967 or with the C330 in 1969, when the click-stop shutter reached it, its true weight without caps, a list price in any currency, and why Mamiya never gave it an auto-cocking shutter.

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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 250mm f/6.3 (C-series TLR)? We'd love to feature it (with credit).

Live listings

Asking price, USD: a median of $190 across 9 fixed-price listings on 2026-09-21 (middle half $110–$220). First day tracked.

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

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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 180mm f/4.5 (C-series TLR) · Mamiya-Sekor 135mm f/4.5 (C-series TLR) · Mamiya-Sekor 55mm f/4.5 (C-series TLR) · Mamiya-Sekor 65mm f/3.5 (C-series TLR)

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.