Biometar 80mm f/2.8 (35mm SLR, 1948 design)

Carl Zeiss Jena · M42 + Exakta · 1951

Also known as: Carl Zeiss Jena Biometar 80mm f/2.8 · Carl Zeiss Jena Biometar 2,8/80 · Carl Zeiss Jena Biometar 2.8/80 · CZJ Biometar 2,8/80 · Biometar 2,8/80 · Biometar 2.8/80 · Biometar 2.8 80 · Biometar 80mm f/2.8 · Biometar 80mm f2.8 · Biometar 1:2,8 f=80mm · Biometar 80 M42 · Biometar 80 Exakta · Biometar 80 Praktina · Jena Bm 2.8/80 · Bm 1:2,8 f=80 · ビオメター 80mm F2.8 · カールツァイスイエナビオメター 80mm F2.8

Variants & identification

Variant	Mount	Years	Serial ranges	Production
M42 preset, aluminium	M42	1951	3585656 — aluminium, T, M42 (Kleinanzeigen, September 2026) 3701540 — red T, preset, 12 blades, M42 (Kleinanzeigen, September 2026) 4234954 — the Wolfen museum's lens, recorded as M42 thread (see notes)	—
Exakta preset, aluminium	Exakta	—	367xxxx — red T; the lens Kröger photographs and captions as the Exakta version (the front-ring view on the same page reads 3674649) 4729633 — no T, red feet scale above the metre scale, GERMANY engraved on the barrel (Kleinanzeigen, October 2026)	—
Praktina IIA, fully automatic (ASB), 1959	Praktina bayonet	1959	—	—
Exakta automatic (spring diaphragm)	Exakta	—	—	—
M42 automatic (pressure-pin diaphragm, ADB)	M42	1960	—	—
Export engraving 'Bm … aus JENA'	Exakta	—	—	—
Exakta automatic, zebra trim	Exakta	—	—	—

The family's dimensions, weight, filter and closest focus are from VEB Carl Zeiss Jena's English-language pamphlet no. 54-320-2, which pictures the automatic Exakta version: five elements, 30° field, 0.8 m to infinity, click stops f/2.8–22, M49 × 0.75 filter, 63.7 mm long, 65.5 mm across, about 260 g, and "imaging factor compared with F = 50 mm lens: 1.6×". The Wolfen museum, citing Kadlubek's catalogue, gives its preset lens as 5 elements in 4 groups, f/2.8–16, E49, 0.8 m, 60 mm long, 54 mm across and 250 g.
The preset lenses photographed (M42 and Exakta, 1950s and early 1960s) all stop down to f/16. The automatic lenses, in the Zeiss pamphlet and in Kröger's photographs of the Praktina and Exakta versions, stop down to f/22. No minimum aperture is given for the family because it depends on the version.
Dates. The calculation was completed in September 1948 (Kröger). Kröger gives no year for the first SLR mount; the Wolfen museum dates its lens 1951–1965, and the 1951 here follows it. The end is stated two ways by the same author: Kröger's German page says the Exakta and M42 lenses were made until the mid-1960s, his English page that the 35mm Biometars went out of production in the second half of the 1960s. The DDR price list still carries an automatic version at 245 Mark in 1967. No end year is given here.
Zebra. Kröger writes that at the very end the Exakta and M42 lenses were briefly made in zebra trim ("Flachnutenrändel", flat-grooved knurling), and his German page pictures an Exakta automatic lens in that trim, which is the zebra variant here. No zebra M42 lens was found. Zebra Biometar 80s are common in Pentacon Six mount, and a zebra lens with a large bayonet and a 58 mm filter is the 6×6 lens.
Praktina in the 1950s. Kröger lists the Praktina with the Praktica and Exakta as cameras the lens was mounted for, and the Wolfen record says its lens is "used for the Praktina" while giving an M42 thread. No preset Praktina-bayonet Biometar was found; only the 1959 ASB lens is a variant.
The Contax rangefinder Biometar 80. Kröger's English essay pictures a Biometar 1:2,8 f=8cm T in Contax mount, no. 3318480 (1949–52 band; photographs by Stefan Baumgartner), says it was "just made for a short period", and calls it, with the Biometar 2,8/35 for the Contax IIa, one of "the two rarest Biometars ever made". It is the same focal length and family of design but a rangefinder lens, and is not a variant on this SLR page.
Also the 1948 calculation, and not variants here: the 2,000 lenses delivered to Franke & Heidecke in 1950–52 as the fixed taking lens of the Rolleiflex 2.8, and the small numbers mounted for the Zeiss Ikon AK16 16mm cine camera (Kröger).
The 1956 Biometar 2,8/80 for the Praktisix and Pentacon Six is a different lens: calculation completed 5 June 1956, patent DD 17,933 filed 15 January 1957, a much larger front element and new high-index glasses, at least 208,800 made by the end of the GDR by Kröger's count. JAPB writes that the 35mm lenses "initially used an older design" which "was modernised in around 1957"; Kröger, working from the factory papers, says the 35mm lenses went on using the 1948 calculation after 1956, with a little-used second calculation of 9 October 1950, and that the 1959 Praktina ASB lens was still the 1948 design. This page follows Kröger. JAPB's naming article also says the design was "finalised in 1941"; Kröger shows a 1941 trial (V1941 Nr. 7, a 2,8/35 cm lens with the Biotar's rear cemented group replaced by a single negative element) only as the starting point of the type.

How to tell them apart (expand)

Five elements, 80 mm, f/2.8, 0.8 m closest focus and a 49 mm filter. The 6×6 Biometar 80 of 1956 focuses to 1 m, takes a 58 mm filter and has a much larger front element
Never multicoated: an MC Biometar 80 is always a 6×6 lens
Preset lenses stop down to f/16; the automatic lenses to f/22²
Export lenses for the West read Bm 1:2,8 f=80 and aus JENA in place of Carl Zeiss Jena Biometar

M42 preset, aluminium:

42 mm screw thread. Aluminium barrel with a scalloped focusing grip; at the front a knurled ring engraved 16–2.8, read against a red index on the name ring, and behind it a second knurled ring carrying a red dot
Front ring engraved Carl Zeiss Jena Biometar 2,8/80 with the number; the earlier lenses add a red T for the coating
Stops down to f/16, not f/22; distance scale to 0.8 m²
12-blade diaphragm on no. 3701540 (seller's description). The Wolfen museum gives no. 4234954 as 5 elements in 4 groups, preset, f/2.8–16, E49, 0.8 m, 60 mm long, 54 mm across, 250 g¹

Exakta preset, aluminium:

Exakta bayonet at the rear; otherwise the same aluminium preset barrel, scalloped grip and knurled front rings as the M42 lens
Stops down to f/16; distance scale to 0.8 m (2.6 ft on the lenses with a feet scale)²

Praktina IIA, fully automatic (ASB), 1959:

Praktina breech bayonet, with the camera-driven fully automatic diaphragm (ASB) of the Praktina IIA
Silver barrel with a black grained band round the front, red feet and black metre scales, f/2.8–22, 0.8 m (Kröger's photograph)
Still the 1948 optics, unlike the Praktisix lens of the same name launched alongside it, whose front element Kröger shows to be much larger

Exakta automatic (spring diaphragm):

Exakta bayonet, with a release plunger on the side of the barrel: the whole spring mechanism sits in the lens, which closes the diaphragm and then trips the camera (Kröger)
Click-stop diaphragm f/2.8–22, 0.8 m, M49 × 0.75 filter, 63.7 mm long, 65.5 mm across, about 260 g (Zeiss leaflet 54-320-2)¹
The leaflet pictures it with the plunger on the left of the barrel and a grained band round the front; the Bm-engraved example Kröger photographs, and a second black one on his German page, have a raised diamond-pattern grip

M42 automatic (pressure-pin diaphragm, ADB):

42 mm thread with the automatic pressure-pin diaphragm (Druckblende) that a pin in the camera body presses to stop the lens down
Kröger's cut drawing of this version shows the same five elements in four groups as the preset lens, with the stop between the cemented pair and the thin meniscus
No photographed example was found, so its barrel finish and minimum aperture are not confirmed²

Export engraving 'Bm … aus JENA':

Front ring reads Bm 1:2,8 f=80 and aus JENA: neither the Biometar name nor Carl Zeiss appears
The example photographed is an automatic Exakta lens on an Elbaflex VX1000: black barrel with a raised diamond-pattern grip, release plunger, f/2.8–22, 0.8 m / 2.6 ft

Exakta automatic, zebra trim:

Focusing grip and aperture ring knurled in alternating black and bright stripes (zebra) on a black barrel, with the Exakta release plunger on the side
Red feet and white metre figures to 0.8 m / 2.6 ft, depth-of-field scale and aperture ring to f/22, as on the black automatic lens (Kröger's photograph)

M42 preset, aluminium: Three of the four 35mm Biometars on offer on Kleinanzeigen in late October 2026 were M42 preset lenses. The Industrie- und Filmmuseum Wolfen dates its example 1951–1965 and cites Kadlubek's lens catalogue; that 1951 is the earliest date any source gives for the SLR lens. Its record contradicts itself: it says the lens is used on the Praktina but gives the mount as M42 thread. The DDR price lists carry a preset Biometar at 248 Mark in 1957, 254 in 1959 and 210 from June 1960. Two of the three M42 lenses offered on Kleinanzeigen in July–September 2026 had a focusing helicoid that was stuck or nearly so.
Exakta preset, aluminium: Kröger names the Exakta and the 42mm thread as the two mounts the lens was made in until the 1960s. No. 4729633, offered in Berlin in October 2026 as an early aluminium Exakta lens with its red-lined case, shows the change seen on the later preset lenses: the T has gone from the front ring and a red feet scale sits above the metre scale.
Praktina IIA, fully automatic (ASB), 1959: Shown at the Leipzig spring fair of 1959 for the Praktina IIA. Kröger stresses that this ASB lens kept the 1948 calculation while the Praktisix lens, launched at the same time, was the new 1956 design, so that Jena then had two optically different Biometar 2,8/80 ASB lenses. The Praktina IIA itself was dropped in the reorganisation of the Dresden camera works that formed VEB Kamera- und Kinowerke. Kröger also lists the Praktina among the cameras the lens was mounted for before the automatic versions, but no earlier Praktina example was found.⁵
Exakta automatic (spring diaphragm): Kröger's English essay dates the fully automatic 35mm Biometars once to spring 1959, alongside the Praktina lens, and once to "since 1960" for the Exakta, Praktina IIA and M42 mounts together. A VEB Carl Zeiss Jena English-language leaflet, pamphlet no. 54-320-2, shows this version with the Exakta release and gives the specifications above. The DDR price list of 1967 carries the automatic Biometar ("Automatische Spring-/Druckblende", covering the Exakta spring and M42 pressure-pin versions) at 245 Mark. See the next two rows for the M42 counterpart and the export engraving.³
M42 automatic (pressure-pin diaphragm, ADB): Kröger's English essay says that from 1960 the 1948 Biometar went into mounts with fully automatic diaphragms for the Exakta, the Praktina IIA and the Praktica M42 thread, and prints his cut drawing of the M42 lens with ADB. The 1967 DDR price list covers it with the Exakta automatic at 245 Mark. No photographed M42 automatic example was found.
Export engraving 'Bm … aus JENA': Kröger writes that in the 1950s Jena shortened the Biometar name to "Jena Bm" to stay safe in its trademark dispute with Zeiss Oberkochen, as it did with "Jena T", "Jena S" and "Jena B"; the postwar Flektogon name needed no such cutting. The one 35mm example found is the Exakta automatic lens Kröger photographs. Praktisix lenses carry the same "Bm" ring, so a "Bm 1:2,8 f=80" alone does not identify the 35mm lens. No Bm-engraved M42 lens was found.
Exakta automatic, zebra trim: Kröger writes that at the very end the Exakta and M42 lenses were briefly made in zebra trim ("Flachnutenrändel", flat-grooved knurling), and beside that remark his German page pictures, without captions, a black Exakta automatic lens with a raised diamond-pattern grip and one in zebra trim. Neither photograph shows the name ring; the 0.8 m scale and f/2.8 aperture match the leaflet's Biometar. No zebra M42 lens was found.⁴

Serial-range notes

the whole number: Jena drew every lens number from one running sequence, so a Biometar is dated against camera-wiki's postwar Jena bands, not by counting within the model: 3,200,000–3,470,000 = 1949–52; 3,470,000–4,000,000 = 1952–55; 4,000,000–5,000,000 = 1955–58; 5,000,000–6,000,000 = 1958–61; 6,000,000–7,000,000 = 1961–64. The bands are three years wide and approximate, so a number dates a lens only roughly.
3585656, 367xxxx, 3701540, 4234954: The T-marked aluminium preset lenses seen for this page, M42 and Exakta, all in the 1952–55 and 1955–58 bands. Two of them (367xxxx and 3701540) have a metre-only distance scale; the Wolfen museum's photograph of no. 4234954 shows the T together with a feet scale engraved in black above the metre scale.
4729633, 6243639: No T on the front ring, and the feet scale above the metre scale now in red, on the same aluminium preset barrel. No. 4729633 is an Exakta lens (1955–58 band); no. 6243639, which Kröger photographs without naming its mount, falls in the 1961–64 band, so the preset lens was still being made after the automatic versions arrived and after the 1960 price cut.
3318480: Not one of this page's lenses: a Biometar 1:2,8 f=8cm T in Contax rangefinder mount, pictured on a Contax II on Kröger's English page (photograph by Stefan Baumgartner; 1949–52 band). See the table notes.

Specifications

Formula: Biometar: five elements in four groups, a Biotar whose rear cemented pair is replaced by one thin, strongly curved negative meniscus
Designed by: Harry Zöllner — head of the Zeiss Jena photo-optics department; led the design, completed September 1948, and proposed the name Biometar · Rudolf Solisch — co-designer in Kröger's English essay; his German page says only that Solisch probably did the actual computation, as he did for the Flektogon
Construction: 5 elements / 4 groups
Aperture range: f/2.8
Min. focus: 0.8 m
Dimensions: 65.5 × 63.7 mm
Weight: 260 g
Filter: 49 mm (0.75 mm pitch)
Years manufactured: 1951
Country: East Germany (VEB Carl Zeiss Jena)
Coating: Single-layer coating, marked by a red T on the earlier lenses (seen up to no. 4234954); later lenses (from no. 4729633 seen) carry no T
Material: Aluminium barrel on the preset lenses
Original price: 248 Mark (GDR, preset version, 1957 price list); 254 Mark in 1959 and 210 Mark from June 1960; the automatic version 245 Mark in 1967. From the DDR price lists as transcribed by Marco Kröger. No Western list price found.

What reviewers say

Marco Kröger (zeissikonveb.de) (blog) — Little wanted in its day, because amateurs preferred a "proper" long telephoto and bought the cheaper automatic Sonnar 3.5/135 instead, which he regrets: a high-quality, dependable and very versatile supplementary lens that keeps its correction close up, and once you are used to the short portrait length you leave the normal lens at home. via machine translation — corrections welcome

Optical formula — Biometar: five elements in four groups, a Biotar whose rear cemented pair is replaced by one thin, strongly curved negative meniscus

History

The Biometar 2,8/80 found on M42 and Exakta reflexes is not the Pentacon Six lens of the same name. It is the original Biometar, whose calculation Harry Zöllner’s photo-optics department at Zeiss Jena completed in September 1948 for Franke & Heidecke’s Rolleiflex 2.8. Zöllner took the Biotar and replaced its rear cemented pair with a single very thin, strongly curved negative meniscus. The result has five elements in four groups and was aimed not at speed but at an even correction across a wider field than a Tessar could manage. Marco Kröger, working from the Jena factory papers, counts only 2,000 lenses delivered to Braunschweig between 1950 and 1952, as the two German states and the two Zeiss firms moved apart. Jena then kept making the lens as a longer accessory lens for the Dresden 35mm reflexes, which Kröger lists as the Praktica, the Exakta and the Praktina (the 42mm-thread lens fits the Contax S line as well), and in small numbers for the AK16 cine camera. On 35mm it is a short telephoto: Zeiss’s own leaflet gives a 30° field and 1.6 times the image size of a 50mm lens.

Its history explains the confusion of names. Jena did not patent the 1948 design. In March 1952 Schneider filed a West German patent on the same layout, and the Xenotar it made for the Rolleiflex is, in Kröger’s words, shape-wise virtually identical. Kröger thinks Rudolf Solisch, who did the computing in Zöllner’s department and later went to Schneider, took the type with him, though Solisch is not named in that patent. In June 1956 Zöllner finished a completely new Biometar 2,8/80 for the Praktisix, with a much larger front element and new high-index glasses, and filed a patent on it in January 1957. From spring 1959 Jena therefore made two optically different Biometar 80s. The 35mm lenses, including the fully automatic Praktina IIA lens shown at the 1959 Leipzig fair, kept the 1948 calculation, with a second calculation of October 1950 used only occasionally. JAPB’s statement that the 35mm design was modernised around 1957 is at odds with this; Kröger’s account is the better evidenced, and this page follows it.

The versions divide by diaphragm. The preset lenses have an aluminium barrel with a scalloped focusing grip and two knurled rings at the front, stop down to f/16 and focus to 0.8 m. They were made with the 42mm thread and the Exakta bayonet, and on the earlier lenses the front ring carries a red T. A feet scale then appears above the metre scale, first in black with the T still present, later in red once the T has gone, and one lens numbered in the early 1960s shows that the preset barrel outlived the arrival of the automatics. From 1959–60 Jena put the same optics into fully automatic mounts: an ASB lens for the Praktina IIA, an Exakta lens with a release plunger on the barrel, and an M42 lens with the pressure-pin diaphragm. The Praktina and Exakta lenses photographed stop down to f/22. Lenses for Western markets were engraved “Bm 1:2,8 f=80” and “aus JENA”, one of the shortened names Jena used during the trademark dispute with Oberkochen. Kröger adds that the last Exakta and M42 lenses came briefly in zebra trim, and pictures an Exakta automatic lens in it. The lens sold slowly. Kröger blames its price of 248 Mark and its modest telephoto effect: amateurs wanted a long lens and chose, for example, the automatic Sonnar 3.5/135, which cost slightly less. The price lists show 248 Mark in 1957 and 210 Mark after the cut of June 1960. Kröger’s German page ends production in the mid-1960s and his English page in their second half, and the 1967 price list still carries an automatic version.

The two things to settle when buying are which Biometar it is and whether its helicoid moves. Of seventeen Biometar 80s on Kleinanzeigen in late October 2026, thirteen were the 6×6 lens. It has a large Praktisix or Pentacon Six bayonet and a 58 mm filter, was multicoated in its later black versions, and focuses no closer than 1 m. The 35mm lens takes a 49 mm filter, focuses to 0.8 m and is never marked MC. Among the preset lenses, an M42 lens has a plain thread and an Exakta lens a bayonet with the Exakta tabs; Praktina lenses need a Praktina body or adapter. Two of the three M42 lenses offered in Germany in mid-2026 had a focusing helicoid that was seized or nearly so. On a preset lens, check that the preset ring stops the aperture where it is set. Kröger regrets that it sold so poorly: in his view it is a high-quality, dependable and versatile lens, good close up because its correction holds at larger magnifications, and a natural portrait length.

Several questions remain open: the year the first SLR lens was delivered; production figures by mount; a zebra M42 lens; a “Bm”-engraved M42 lens; whether a preset Praktina version existed in the 1950s; and how to recognise the few lenses built to the October 1950 calculation.

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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 Biometar 80mm f/2.8 (35mm SLR, 1948 design)? We'd love to feature it (with credit).

Live listings

100【良上品希少】EXA Carl Zeiss Jena Biometar 2,8/80mm ツァイスビオメター 1964年製 f2.8 — from ¥29,980 · Yahoo! Auctions Japan · auction 2026-11-01

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