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

Zuiko 50mm f/1.2

Olympus · Olympus OM · 1982

single source, unconfirmed via machine translation — corrections welcome

Known as “たまたま”

Also known as: Zuiko Auto-S 50mm F1.2 · OM-System Zuiko Auto-S 50mm 1:1.2 · Olympus OM Zuiko 50mm f/1.2 · Olympus 50mm 1.2 OM · Zuiko 50mm 1:1.2 · ズイコー 50mm F1.2 · ZUIKO AUTO-S 50mm F1.2

Variants & identification

Variant Mount Years Serial ranges Production
Zuiko Auto-S 50mm f/1.2 Olympus OM 1982 — —
  1. Launch year. mir.com.my says the 55mm f/1.2 was "revised in 1982 with a marginally shorter focal length at 50mm", and lens-db files the lens under 1982; om-mania, muuseo and lensreview.xyz, all Japanese, give 1983. The Olympus sales information file at olympus.dementix.org, which would settle it, returned a server error throughout the drafting of this page. 1982 is used, with 1983 recorded here as the Japanese sources' date.
  2. Weight. mir.com.my's spec table gives 310g and then says the redesign reduced the weight "to merely 285g in the current version"; the 310g figure is the 55mm f/1.2's, carried over. Wikipedia, om-mania and phillipreeve give 285g, which is used.
  3. Price. om-mania alone gives a launch price of ¥80,000, undated. It is entered with the single-source badge.
  4. The optical analysis by 高山仁 on lensreview.xyz works from Japanese patent application 特開昭53-69031 (filed 1978 by the number), which he identifies as this lens's design. That identification is his; Olympus's own literature for the lens has not been read here.
How to tell them apart (expand)
  • The only OM f/1.2 with a 49mm filter and a 50mm engraving; the earlier G.Zuiko 55mm f/1.2 has a 55mm filter, a letter prefix and a longer barrel.
  • No version differences are recorded; one engraving, multicoated, 285g

Zuiko Auto-S 50mm f/1.2:

  • Engraved ZUIKO AUTO-S 50mm 1:1.2 with no letter prefix and no MC: it arrived after Olympus had dropped both markings, and is multicoated throughout
  • 49mm filter where the 55mm f/1.2 it replaced took 55mm; 43mm long and 65mm across against the 55's 47mm, and 285g against 310g
  • Eight aperture blades, f/1.2 to f/16 in whole-stop detents, 0.45m close focus

Specifications

Formula
7 elements in 6 groups, a complete redesign of the 55mm f/1.2; the design analysed by lensreview.xyz from Japanese patent application 特開昭53-69031
Construction
7 elements / 6 groups
Aperture range
f/1.2–f/16
Diaphragm blades
8
Min. focus
0.45 m
Dimensions
65 × 43 mm
Weight
285 g
Filter
49 mm
Years manufactured
1982
Country
Japan
Coating
Multicoated; Olympus's brochure text quoted by mir.com.my cites high-index low-dispersion glass and multi-layer coatings
Original price
¥80,000 (launch, om-mania) (today ¥110,000)

What reviewers say

Optical Ratings

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

Spherical aberration
heavy halation open
Vignetting
light corners
Flare & ghosting
extreme near sun
Coma
strong sagittal coma

History

Olympus had sold an f/1.2 standard since about 1974, the G.Zuiko 55mm f/1.2, a seven-in-six lens with a 55mm filter that did not match anything else in the system. In 1982, by mir.com.my’s account, or 1983 by the Japanese sources, it was replaced by a new computation at 50mm: still seven elements in six groups, but 4mm shorter, 25g lighter at 285g, and behind the 49mm filter the f/1.4 and f/1.8 already used. om-mania records the designer Yonetsutani’s remark that the OM mount had been sized from the start to pass an f/1.2 cone, and this is the lens that finally used the allowance without a bulge. Japanese owners call it たまたま, for its rounded shape.

It carries one engraving, ZUIKO AUTO-S 50mm 1:1.2, with neither a letter prefix nor an MC mark, because Olympus had dropped both conventions before it arrived. It is multicoated throughout, and no source consulted records any change to the barrel or the glass across its production. Olympus’s brochure text, as mir quotes it, credits high-index low-dispersion glass and multi-layer coatings for its low-light performance. Eight blades, f/16 minimum, 0.45m close focus. om-mania gives a launch price of ¥80,000, which no second source confirms.

The one analysis of what is inside comes from 高山仁 on lensreview.xyz, working from the Japanese patent application he identifies with the lens. His reading is that the spherical aberration was left deliberately undercorrected in the outer zone and held down in the middle, which is what gives the soft, glowing plane of focus at f/1.2 without the whole image falling apart, and that sagittal coma flare runs off his chart and produces V-shaped point sources at the edges. He describes it as a lens to enjoy twice, once open and once stopped down.

The reviewers agree with him. Braddon-Mitchell finds a lot of halation at f/1.2 even in the centre, though with less colour in it than he expected, and excellent central performance by f/5.6; Rob Lambert on a 36MP sensor finds it “all tidied up at f2” and calls it the best Zuiko he has used; the Naniwa dealer blog finds the bleeding outlines and busy bokeh gone by f/2.8. Veiling flare with the sun just outside the frame is the common complaint, as it is for every fast normal of the period, and bubble-edged bokeh at f/1.2 is either the point or the problem depending on the reviewer. Against the 55mm, Braddon-Mitchell’s guide says the older lens is less sharp and has funkier bokeh; against the f/1.4, everyone says the f/1.2 is the one that stops down into an excellent all-rounder.

Buying one: prices have climbed to what Lucy Lumen on Fstoppers calls Leica money for a clean example, so check the coatings on the front element for cleaning marks, the rear element for the damage that sold muuseo’s example at a discount, and the aperture for oil. No Commons photograph of the lens could be verified for this page, and the launch date remains split between 1982 and 1983 until the Olympus sales information file at dementix.org comes back online.

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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 Zuiko 50mm f/1.2? We'd love to feature it (with credit).

Live listings

Asking price, USD: a median of $500 across 11 fixed-price listings on 2026-09-18 (middle half $470–$550). First day tracked.

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

Show 4 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 2026-09-18. Links go to the shop or marketplace that carries the item.

Related: Zuiko 50mm f/1.4 · Zuiko 50mm f/1.8 · Zuiko 55mm f/1.2 · Zuiko 85mm f/2

Sources (13)

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.