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

Mamiya-Sekor Zoom C 105-210mm f/4.5 (645)

Mamiya · Mamiya 645 · 1980

single source, unconfirmed

Also known as: Mamiya-Sekor Zoom C 105-210mm f/4.5 · Mamiya-Sekor Zoom ULD C 105-210mm f/4.5 · Mamiya Sekor C 105-210mm f4.5 ULD · Mamiya 645 105-210mm f/4.5 · Sekor C 105-210/4.5 · マミヤ セコールC ズーム 105-210mm F4.5 · マミヤ セコール ULD C 105-210mm F4.5 · マミヤ 645 105-210mm F4.5

Variants & identification

Variant Mount Years Serial ranges Production
Mamiya-Sekor Zoom C 105-210mm f/4.5 (original, 77 mm filter) Mamiya 645 — — —
Mamiya-Sekor Zoom ULD C 105-210mm f/4.5 Mamiya 645 1983 — —
  1. The ULD version's optical construction, angle of view, minimum aperture, closest focus, magnification, filter size, hood, dimensions and weight are from Mamiya's own tables (the M645 1000S manual and Sekor C instruction sheet at butkus.org, and the 645 Pro-era product sheet). The family spec fields carry the ULD lens's figures, since it is the version Mamiya tabulated and the one that ran to the end of the system.
  2. The original lens's figures (15 elements in 11 groups, 2.5 m, 6 blades, 208 × 80 mm, 1,218 g) come from Kamerastore's listing, partly matched by awane-photo (15 elements, 77 mm, 1,220 g); Mamiya's chart confirms only the 77 mm filter and the separate hood. Treat them as single-source.
  3. Dating: awane-photo says the original appeared in the early 1980s and the ULD in the 1983 catalogues; Mamiya's undated M645J-era chart, which shows the M645J of 1979, has the original and no ULD. 1980 is the family year as the earliest point consistent with both; the ULD's 1983 rests on awane-photo alone. The page carries the single-source flag.
  4. The ULD version's 9 aperture blades are Wikipedia's figure, matched by Kamerastore; Mamiya's tables give no blade count.
How to tell them apart (expand)
  • Filter thread tells the versions apart at a glance: 77 mm with a separate hood on the original, 58 mm with a built-in hood on the ULD
  • ULD engraved on the second version's name ring; neither version has an N
  • 875 g against roughly 1,220 g: the ULD lens is a full third lighter
  • The autofocus 105-210 ULD for the 645 AF has no aperture ring and the AF bayonet

Mamiya-Sekor Zoom C 105-210mm f/4.5 (original, 77 mm filter):

  • No ULD on the name ring; 77 mm filter thread with a separate slip-on hood (Mamiya's M645J-era system chart)
  • 15 elements in 11 groups, 2.5 m closest focus, 208 × 80 mm, 1,218 g (Kamerastore); awane-photo gives 11群15枚, φ77 and 1,220 g with a detachable hood
  • Mamiya's Sekor C sheet: 'Special hoods are required for the ... Zoom 105-210mm', a hood that the ULD version's built-in one made unnecessary

Mamiya-Sekor Zoom ULD C 105-210mm f/4.5:

  • ULD on the name ring; 58 mm filter thread and a built-in pull-out hood
  • Mamiya's tables: 13 elements in 11 groups, 36°–19° angle of view, f/4.5–32, 180 cm closest focus, 0.07–0.14×, 58 mm filter, built-on hood, 158 × 74.5 mm, 875 g
  • Non-extending barrel: the length does not change with focal length (Nordhaug); a metal barrel without an N suffix even in the 645 Pro years

Specifications

Construction
13 elements / 11 groups
Aperture range
f/4.5–f/32
Diaphragm blades
9
Min. focus
1.8 m
Dimensions
74.5 × 158 mm
Weight
875 g
Filter
58 mm
Years manufactured
1980
Country
Japan
Coating
Multi-coated on both versions: Mamiya's manual says all the lenses for the camera have been multi-coated, and the C in Sekor C denotes multicoating (Wikipedia); the ULD version adds an ultra-low-dispersion element

What reviewers say

Optical Ratings

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

Chromatic aberration
very low
Optical formula

History

The 105-210mm f/4.5 is the telephoto zoom of Mamiya’s manual-focus 645 system, a 65–130mm equivalent on 35mm film by Mamiya’s table, and the best-regarded of the three zooms the line had. In its ULD form Mamiya’s own figures are 13 elements in 11 groups, angles of view from 36° to 19°, a constant f/4.5 to f/32, closest focus at 180 cm for 0.07× to 0.14×, a 58 mm filter thread, a built-in pull-out hood, and 875 g in a barrel 74.5 mm across and 158 mm long that does not extend when zoomed. The M645 1000S manual prints a cross-section.

Two versions exist and they are different lenses under one name. The original Mamiya-Sekor Zoom C 105-210mm f/4.5 is on Mamiya’s M645J-era system chart with a 77 mm filter and a separate slip-on hood, and the awane-photo Camera Museum puts it in the early 1980s: 15 elements in 11 groups, about 1.2 kg, by Kamerastore’s and awane’s figures, since no Mamiya table for it was found. The Mamiya-Sekor Zoom ULD C 105-210mm f/4.5 replaced it by the 1983 catalogues, with an ultra-low-dispersion element, two elements fewer, the hood built in, the filter down to 58 mm and a third of the weight gone. It is the version in Mamiya’s 1000S manual, its Sekor C sheet, the Pro-era product sheet and the 645 Pro manual’s 1992 list, and it never took an N suffix. The dates rest on one source and the page says so.

The reviewers agree about the ULD lens, and none of them tested the original. Dag Ole Nordhaug, on a Hasselblad X2D, found it slightly soft at 105mm, sharpening from about 110–120mm, and ‘utterly impressive’ across the whole frame at 150 and 210mm, with colour fringing as low as a modern Hasselblad HC prime’s; cropped to match, its long end was ‘a draw’ with the ULD 300mm f/5.6 prime. Tony Howell, on a 39-megapixel P45 back, saw contrast drop wide open, the best results at f/8, better toward 210mm, and slight fringing that only shows on big prints; 8 out of 10 and ‘a recommended lens’. An MFlenses thread calls it ‘sharp from wide open’ and ‘a seriously good lens’. Nordhaug’s used-price range was $80 to $300.

The filter thread is the first thing to read in a listing: 77 mm with a loose hood is the original, 58 mm with a sliding hood is the ULD. On either, work the zoom and focus rings through their full travel for stiff grease, check for haze between the many groups, see that the built-in hood slides, that the Auto/Manual lever is back on A and that the blades snap shut at f/32. The lens mounts on the 645AF and later bodies but meters only stopped down there, and the autofocus Mamiya AF 105-210mm f/4.5 ULD of 2000 is a different mount that will not fit a manual-focus body.

What remains open: a Mamiya table for the original version, a second source for both launch years, list prices in any currency, and a discontinuation date for the ULD lens.

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 Zoom C 105-210mm f/4.5 (645)? We'd love to feature it (with credit).

Live listings

Asking price, USD: a median of $110 across 7 fixed-price listings on 2026-09-21 (middle half $70–$120). 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 Zoom C 55-110mm f/4.5 N (645) · Mamiya-Sekor C 300mm f/5.6 (645) · Mamiya-Sekor C 210mm f/4 (645) · Mamiya-Sekor C 150mm f/3.5 (645) · Mamiya-Sekor C 110mm f/2.8 (645) · Mamiya APO A 200mm f/2.8 (645) · Mamiya-Sekor C 500mm f/5.6 (645)

Sources (16)

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.