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

RE Auto-Topcor 25mm f/3.5

Topcon · Exakta · 1963 · Retrofocus

via machine translation — corrections welcome

Also known as: RE Auto-Topcor 25mm f/3.5 · RE Auto-Topcor 25mm f3.5 · RE Auto Topcor 25mm f3.5 · RE Auto Topcor 25mm f/3.5 · RE.Auto-Topcor 25mm f3.5 · RE. Auto-Topcor 25mm f3.5 · RE. Auto-Topcor 2.5cm f3.5 · RE Auto-Topcor 2.5cm f3.5 · RE Auto Topcor 2.5cm f3.5 · RE. Auto-Topcor 1:3.5 f=2.5cm · RE. Auto-Topcor 1:3.5 f=25mm · RE Auto-Topcor 3.5/25 · Auto-Topcor 3.5/25 · Auto-Topcor 25mm f3.5 · Auto Topcor 25mm f3.5 · Auto-Topcor 2.5cm f3.5 · Topcon 25mm f3.5 RE Auto-Topcor · Topcon 25mm f3.5 RE Auto Topcor · Topcon 2.5cm f3.5 RE. Auto-Topcor · Topcon 2.5cm f3.5 RE Auto-Topcor · Topcon RE Auto-Topcor 25mm f3.5 · Topcon RE Auto-Topcor 2.5cm f3.5 · Topcon RE Auto-Topcor 2.5cm F3.5 (25mm) · Tokyo Kogaku RE Auto-Topcor 25mm f3.5 · Tokyo Kogaku Topcor 25mm f3.5 · Topcon 25mm f3.5 · Topcon 25mm f/3.5 · Topcon 2.5cm f3.5 · Topcon 25mm 1:3.5 · Topcor 25mm f3.5 · Topcor 25mm f/3.5 · Topcor 2.5cm f3.5 · Topcor 25mm 1:3.5 · Topcor 3.5/25 · Topcor 25 f3.5 · Topcor Automatic 25mm f3.5 · Beseler Topcon 25mm f3.5 · Beseler Topcor 25mm f3.5 · トプコール 25mm F3.5 · トプコール 2.5cm F3.5 · REオートトプコール 25mm F3.5 · RE オートトプコール 25mm F3.5 · REオートトプコール 2.5cm F3.5 · オートトプコール 25mm F3.5 · オートトプコール 2.5cm F3.5 · トプコン 25mm F3.5 · トプコン 2.5cm F3.5 · トプコン RE Auto-Topcor 25mm F3.5 · トプコン REオートトプコール 25mm F3.5

Variants & identification

Variant Mount Years Serial ranges Production
RE. Auto-Topcor 1:3.5 f=2.5cm (later f=25mm), chrome Exakta 1963 — —
RE. Auto-Topcor 1:3.5 f=2.5cm, black (export batch) Exakta 1963–1964 — Very small; no figure known (Topcon Club: 'unquestionably very few')
  1. Date: Topcon Club says the 25mm made its debut with the RE Super (1963), and calls it the first retrofocus ultra-wide made for a Japanese SLR (Japanese text: 国産一眼レフカメラ用交換レンズでは初; the English text on the same page says 'the first, world wide'). Beseler's Topcon catalogue, © 1966, lists it as the 25mm f/3.5 Topcor Automatic. English Wikipedia gives 'introduced 1965' without a source. Maxifiche dates the RE Auto-Topcor series as a whole 1963–1976 without dating each lens. No end date found.
  2. Specifications: 7 elements on every source (Maxifiche, Paillard, Beseler 1966, Kamerastore) and 82° on all that give an angle (Maxifiche, Paillard, Beseler 1966). Closest focus 0.16 m (Maxifiche, Kamerastore) or 6½ in (Beseler, Paillard). Aperture f/3.5 to f/22 (Maxifiche; Beseler: click stops to f/22); Kamerastore adds half-stop clicks and 6 blades. Weight: 300 g (Maxifiche), 11¼ oz / 320 g (Paillard), 10½ oz (Beseler 1966), 299 g (Kamerastore). Size: 2 2/16 in long, 2 8/16 in at closest focus (Beseler); 72 × 65 mm (Kamerastore). No source gives the number of groups.
  3. Filters: Paillard says the lens comes with a rear-element UV (or clear) filter that 'forms an optical component of the lens and must be kept in place' unless replaced with another filter, and sold a kit of nine rear filters (#82290, $27.65). Beseler gives 'Rear Bayonet or Series 9 with furnished adapter ring'; Topcon Club says a Series IX filter can be fitted in the hood. Maxifiche gives 'Baïonnette' and a slip-on hood. English Wikipedia's 62 mm filter disagrees with all of these and is not used here.
  4. The R (1957): Topcon Club says the R body has no automatic-diaphragm mechanism of its own; its semi-automatic Auto-Topcors carried it in the lens. The RE Auto-Topcor fits the R's bayonet, but its diaphragm is closed by a lever in the body, which the R lacks, so nothing on the R stops it down. No source describes this lens on an R; the link is kept with that limit.
  5. The Automatic R (RII), RIII and RS (1960–63): Maxifiche says the RII added a diaphragm-closing lever inside the bayonet, and Topcon Club says many RS bodies are found with RE Auto-Topcors. None of these bodies meters through the lens (the RIII and RS take clip-on meters coupled to the shutter speeds; Maxifiche, Topcon Club), so the lens's meter coupling does nothing on them. No source describes the 25mm on these bodies specifically.
  6. RE Super, RE-2, Super D and Super DM: full-aperture focusing and metering, as for every RE Auto-Topcor (Maxifiche); the 25mm was launched with the RE Super. RE200 and RE300 (1977–78): Topcon Club says they keep the RE mount of the RE Super line, with open-aperture TTL metering; they were sold with the new RE Topcor N lenses, but the cameras' own instruction book lists the RE Auto-Topcor 25mm f/3.5 in its table of Topcor lenses, with automatic diaphragm and full-aperture metering.
  7. Exakta bodies: Maxifiche calls the Topcon R's mount a fully compatible Exakta bayonet ('totalement compatible'), which Topcon then developed step by step, and Topcon Club notes that Topcon put its release on the opposite side to Exakta's, so lenses worked by an external arm lose that function when moved between the two. Neither source describes an RE Auto-Topcor on an Exakta body.
How to tell them apart (expand)
  • Engraved RE. Auto-Topcor and 1:3.5 f=2.5cm (or f=25mm on 1970s copies), TOKYO KOGAKU
  • No front filter thread: the domed front element fills the barrel, and filters fit by bayonet at the rear (a UV or clear filter should be in place; it is part of the optics)
  • Fully automatic diaphragm closed by the body's lever; focusing and metering at full aperture on the RE bodies (Maxifiche)
  • Not the smaller RE Auto-Topcor 20mm f/4 (62 mm filter per Paillard; Maxifiche gives a bayonet filter for it too); not the UV Topcors of the leaf-shutter and IC-1 cameras; not the 1970s RE Topcor N lenses

RE. Auto-Topcor 1:3.5 f=2.5cm (later f=25mm), chrome:

  • Satin-chrome barrel (Kamerastore: 'Metal body available in silver grey'); focal length engraved 2.5cm on earlier copies and 25mm from the 1970s (Topcon Club)
  • Very large, strongly domed front element, which leaves no room for a front filter thread; small filters fit by bayonet at the rear of the lens instead (Topcon Club, Paillard, Beseler)
  • Stayed chrome after 1972, when Topcon turned every other lens black with the Super D (Topcon Club)
  • Early serial numbers have four digits, on chrome and black alike (Topcon Club)

RE. Auto-Topcor 1:3.5 f=2.5cm, black (export batch):

  • Black barrel with the 2.5cm engraving; Topcon Club's example carries a serial number one digit shorter than his chrome copy's
  • Never shown in a Topcon catalogue (Topcon Club)

Serial-range notes

Four-digit numbers
Topcon Club says both chrome and black 25mm lenses carried four-digit serial numbers at first, and dates its black copy to 1963–64 on that basis alone. No serial list ties later numbers to years.

Specifications

Formula
Retrofocus
Construction
7 elements
Aperture range
f/3.5–f/22
Diaphragm blades
6
Min. focus
0.16 m
Weight
300 g
Filter
Rear bayonet filters (one always fitted: it is part of the optics); Series IX in the hood
Years manufactured
1963
Country
Japan
Original price
US$200.00 with UV filter, hood and leather case (Paillard Incorporated catalogue no. 80540, list price; the catalogue is undated but lists the Super DM of 1973)

What reviewers say

History

The RE Auto-Topcor 25mm f/3.5 was the ultra-wide that Tokyo Kogaku launched with the Topcon RE Super in 1963. Topcon Club, the Japanese collectors’ site, calls it the first retrofocus ultra-wide made for a Japanese single-lens reflex. The English text on the same page goes further and says the first anywhere. Maxifiche (the French collectors’ sheet), the 1966 catalogue of the American importer Beseler, which sold it as the 25mm f/3.5 Topcor Automatic, and the later Paillard catalogue all give seven elements and an 82° angle of view. It stops down to f/22 and focuses to 0.16 m (6½ in). Like the other RE Auto-Topcors it has a fully automatic diaphragm, closed by the body at the moment of exposure, and a coupling that gives full-aperture metering on the RE Super and later bodies. English Wikipedia dates the lens to 1965 without a source, but Topcon Club ties it to the RE Super’s launch.

The front element is large and strongly domed, so there is no front filter thread. Filters fit by bayonet at the rear of the lens instead. Paillard warns that the rear UV filter supplied with the lens “forms an optical component of the lens and must be kept in place” unless another filter replaces it, and sold a kit of nine rear filters. Beseler supplied an adapter ring for a Series IX filter, and Topcon Club says a Series IX filter can also be fitted in the slip-on hood. Topcon Club found the small rear filters easy to carry. Wikipedia’s 62 mm filter size matches none of this. Paillard’s list price was US$200.00 with the UV filter, hood and leather case, against $272.10 for the 20mm f/4 in the same catalogue.

There are two finishes. Almost every copy is satin chrome. When Topcon turned its lenses black with the Super D of 1972, the 20mm and 25mm alone stayed chrome, and Topcon Club says they ended that way. The engraving changed from 2.5cm to 25mm during the 1970s. That is the only change reported, and no source says the optics changed. The rare version is an early black 2.5cm. Topcon Club pictures one and says a very small number were exported to the United States, apparently in 1963 or 1964. He dates it by its serial number, which has one digit fewer than his chrome copy’s (the early serials of both finishes had four digits). No Topcon catalogue ever showed it, and no production figure is known.

The lens fits every Topcon focal-plane body but does not work fully on all of them. On the RE Super, RE-2, Super D and Super DM it focuses and meters at full aperture. The RE200 and RE300 of 1977–78 keep the same RE mount, and their instruction book lists the 25mm with full-aperture metering. The Automatic R (RII), RIII and RS have a body lever that closes an automatic diaphragm, and Topcon Club says many RS bodies turn up with RE Auto-Topcors, but none of the three meters through the lens and no source describes the 25mm on them. The original R of 1957 has no diaphragm mechanism in the body, so nothing on it would stop this lens down; no source describes that pairing either. The mount is Topcon’s development of the Exakta bayonet. Topcon Club notes that the Topcon release sits on the opposite side to the Exakta’s, so lenses worked by an external arm do not cross between the two, and no source describes an RE Auto-Topcor on an Exakta body. Topcon’s cheaper SLRs (the leaf-shutter Wink Mirror, Uni and Unirex, and the focal-plane IC-1 of 1973) took UV Topcor lenses on a different mount and cannot use this one (Maxifiche).

Topcon Club rates the 25mm’s rendering highly: very three-dimensional, in his view the best of any Topcor in that respect. He also notes that many buyers chose the 25mm because Topcon’s 28mm came much later, which in his view is why the RE Auto 28mm is seldom seen today. When buying, check that a rear filter is fitted, because the lens is computed with one in place. Work the diaphragm from the rear of the mount to make sure it snaps shut and reopens. Check that it focuses to infinity: a copy Kamerastore listed as a “rescue” item did not. Look at the exposed front element for scratches and cleaning marks, and see whether the hood is included. A black 2.5cm is a real rarity and should be checked closely, since the only source for it is a single collector’s account.

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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

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Live listings

Asking price, USD: a median of $320 across 12 fixed-price listings on 2026-11-10 (middle half $250–$430). 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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Listings updated 2026-11-10. Links go to the shop or marketplace that carries the item.

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.