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

Biogon 21mm f/4.5

Carl Zeiss · Contax RF · 1954 · Biogon — symmetrical wide-angle

Also known as: Zeiss Biogon 21mm f/4.5 · Biogon 2.1cm

Variants & identification

Variant Mount Years Serial ranges Production
Oberkochen / Zeiss Opton Contax RF 1954–1961 — No figure published
  1. Introduction date is contested. Pacific Rim Camera says the lens was marketed in 1953; Wikipedia and the collector literature put the first regular-production Biogon at 1954 and tie its launch to Photokina 1954. Both are recorded rather than reconciled; the variant table's 1954 follows the second.
  2. The 21mm f/4.5 Biogon was later made in Contarex mount as well, on the same Oberkochen number sequence. Production figures quoted for the Contarex lens do not apply to the Contax rangefinder version in this entry. Stephen Gandy, who has handled both, reports the Contarex version as the rarer of the two.
  3. The 1954 introduction date is now carried by three sources that do not depend on one another. Stephen Gandy dates it to 1954; the November 1954 issues of Modern Photography and Popular Photography both carried articles on the lens as a new product, which fixes the date from inside the year itself; and Pierpaolo Ghisetti ties the Contax IIa's commercial survival after the Leica M3 to the arrival of the Biogon "appunto nel 1954". Pacific Rim Camera's 1953 marketing date stands unreconciled against all three.
  4. A disagreement about mounts, and the maker's own documents come down on one side of it. Mike Eckman writes that the 1954 lens was "available only in Contax rangefinder and Leica screw mount". Stephen Gandy, writing about the same lens, says the opposite — that a Biogon seen on a Leica is there by way of a repairman's work or a non-focusing Contax-to-LTM adapter — and Ghisetti describes Leica owners fitting it with the Orion adapter ring. Zeiss Ikon's own American price lists agree with Gandy by omission. The Contax price list of 15 February 1956 (CAM-617), the price list of 1 October 1958 (CAM 906) and the dealer catalogue of 15 May 1960 (CAM-891-a) all list "BIOGON f/4.5, 21mm." under the heading "LENSES IN BAYONET MOUNT FOR CONTAX IIa and IIIa", catalogue number 11.1804, and none of the three names a Leica-thread lens of any focal length or mentions Leica at all. That is not proof a screw-mount 21mm was never made — a price list records what was sold, not what existed — but it is the maker listing this lens in one mount and only one, across six years and three documents, and no source consulted shows a factory Leica-thread 21mm Biogon or quotes a serial block for one. Eckman's claim is left standing as his, and it has nothing behind it.
  5. Zeiss Ikon's 1956 specification table gives the lens as 8 elements, a 90° angle of view, a smallest aperture of f/22 and a closest focus of 3 feet, covering approximately 3'1" by 4'8" at that distance.
  6. Ghisetti, reading the Zeiss Ikon catalogues, notes that the Contax camera line was officially closed in 1960 but that lenses went on being supplied until 1962: the 1961/62 Zeiss Ikon catalogue still gives the Contax system five pages and eight lenses, from 21mm to 135mm. The 1961 end date in the table above is the conventional one; the catalogue evidence runs a year past it.
  7. Corroboration searched for and not found: no second source publishes a serial block, a batch list or a production total for the Contax-mount 21mm Biogon. Pacific Rim Camera, Stephen Gandy, Mike Eckman's reprints of the November 1954 magazine coverage, and Ghisetti's version-by-version classification of the Zeiss Contax lenses were all checked. Ghisetti itemises batches for the 50mm, 85mm and 135mm lenses and gives none for the 21mm. A copy is still dated only from the Oberkochen year bands.
How to tell them apart (expand)
  • A deep rear element, as on every symmetrical Biogon
  • One of the very few 21mm lenses of the 1950s for any camera
  • No click stops on the aperture ring — Popular Photography complained in 1954 that it moved by accident
  • A depth-of-field scale engraved only at f/4.5 and f/5.6; at any smaller stop the lens covers nearly its whole focusing range

Oberkochen / Zeiss Opton:

  • Chrome; marked Zeiss Opton or Carl Zeiss
  • Needs its own finder — no Contax frames 21mm

Serial-range notes

the whole number
How to date one. Carl Zeiss drew every photographic lens number from a single running sequence covering all models at once, so a Zeiss lens is dated by reading its number off a serial/year table rather than by counting within its own type — there is no per-model list of the Leitz kind. The table, taken from Wilkinson and Glanfield's A Lens Collector's Vade Mecum, runs the Jena sequence from 173,418 in 1912 to about 2,900,000 in 1942; camera-wiki and Craig Camera publish near-identical copies of it. The 1912 opening is given here as Craig Camera and the Leica Contax blog print it. Camera-wiki transposes it to 137,418, which the Vade Mecum's own quantity column rules out — the blog's copy of the 1912 row reads "173,418 - 200,520 27,102", and only the first reading subtracts to the published 27,102.
10000–3000000, on an Oberkochen barrel
Which sequence this lens belongs to. It is an Oberkochen lens, and Oberkochen began a fresh sequence at 10,000 in 1946 rather than continuing the prewar Jena numbers, which Carl Zeiss Jena in the East carried on from 3,000,000. The West German bands are 10,000–500,000 = 1946–51, 500,000–1,100,000 = 1951–53, 1,100,000–2,600,000 = 1953–59, 2,600,000–3,000,000 = 1959–61. A number in the low millions on this barrel is therefore 1950s, not 1920s — the same figure on a Jena lens would be interwar.
1100000–3000000
The bands that bracket a lens made from 1954 to 1961: 1,100,000–2,600,000 for 1953–1959 and 2,600,000–3,000,000 for 1959–1961. Nothing narrower has been published.
any number near a year boundary
Blocks were allotted to production in sequence, but batches were not always finished in block order, so the published year ranges overlap — 1935 runs to 1,752,303 while 1936 opens at 1,674,882 — and a serial places a lens within a year or two rather than to a month. Pentacon Six sets out the mechanism and points to Hartmut Thiele's Fabrikationsbuch Photooptik, a transcription of the factory books, for batch-level dates.
a letter followed by five digits
Not a lens number at all. That is the Zeiss Ikon CAMERA sequence, inherited from ICA in 1909, which rolls to the next letter at 99,999, reached Z in 1936 and restarted at A. A Contax body number and a Zeiss lens number belong to separate schemes and must never be read against the same table.
no serial list has been published for this lens
No source consulted publishes serial ranges, batch blocks or a production total for the Contax-mount 21mm Biogon. Pacific Rim Camera, which prints batch numbers for the 50mm, 85mm and 135mm Contax lenses, gives none here and states that there are no known variations of the lens — so there are no version boundaries for a serial to mark in the first place. A copy is dated from the Oberkochen table above.

Specifications

Formula
Biogon — symmetrical wide-angle
Designed by
Ludwig Bertele — Computed the original Biogon at Zeiss Ikon Dresden in 1934; recomputed it for Carl Zeiss Oberkochen in 1951, from Switzerland, widening the 2.8cm design's field by ten degrees to reach 21mm. The formula is drawn in US Patent 2,721,499.
Construction
8 elements / 5 groups
Aperture range
f/4.5
Min. focus
0.9 m
Filter
40.5 mm
Years manufactured
1954–1961
Country
Germany
Original price
$269.50 (1954), $199.00 new by May 1957 (today $3,140)

What reviewers say

History

Zeiss offered a 21mm lens for the Contax in the mid-1950s, four years before Leitz had one for the Leica — and when Leitz did, it was Schneider’s Super-Angulon, built on the same symmetrical principle with the same deep rear element and the same consequences for metering.

At f/4.5 it is slow, which symmetrical wide-angles of this era generally were, and it needs its own accessory finder because no Contax shows anything wider than 50mm.

The design is Ludwig Bertele’s, twice over. He computed the first Biogon at 2.8cm for Zeiss Ikon Dresden in 1934; in 1951, living in Switzerland, he recomputed it for Carl Zeiss Oberkochen and widened the field by ten degrees, which is how a 2.8cm design becomes a 21mm one. Eight elements in five air-spaced groups, drawn in US Patent 2,721,499.

It arrived expensive. Popular Photography put the price at $269.50 in November 1954; by May 1957 Olden Camera in New York was advertising it at $199.00 new and $114.25 used. That first price bought the widest lens then made for 35mm photography, and Pierpaolo Ghisetti argues it is why the Contax IIa went on selling after the Leica M3 appeared — professionals bought the camera to get the lens, and Leica owners bought the lens and adapted it.

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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 Biogon 21mm f/4.5? We'd love to feature it (with credit).

Live listings

Asking price, USD: a median of $950 across 30 fixed-price listings on 2026-09-11 (middle half $800–$1,200). Tracked since 2026-09-06, 3 days: unchanged from $950.

By day
DateMedianMiddle halfListings
2026-09-11$950$800–$1,20030
2026-09-10$950$800–$1,20029
2026-09-06$950$760–$1,10031

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 2026-09-11. Links go to the shop or marketplace that carries the item.

Related: Biogon 3.5cm f/2.8 · Super-Angulon 21mm f/4 · Russar MR-2 20mm f/5.6

Sources (15)

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.