Pekka Buttler, 07/2024
Specifications
The table below summarizes the lens’ key specifications (measurements based on pictured lens):
Brand: | Carl Zeiss Jena | Lens name | Biometar 2.8/120 |
Focal length(s)1 | 120 mm | Angle-of-view2 | 36,3 ° (on medium format) |
Maximum Aperture | f/2.8 | In Production | 1958–≈1988 (all variants) |
Lens mounts | Pentacon 6 | Other lens mounts: | Exakta, M42, Praktina |
Length3 | 73,6 mm | Diameter4 | 79,4 mm |
Filter ring diameter | 67 mm | Weight | 482 grams |
Lens element count | 5 | Lens group count | 4 |
Aperture blades (S/R/C)5 | 8 S | Focus throw | 300 ° |
Minimum focusing distance | 1 m | Maximum magnification | 1:10 |
Has manual aperture ring | YES | Has Manual focus ring | YES |
Further notes:
• The 120 mm Biometar is the ‘big brother’ of the 80 mm Biometar which was the standard lens for the Praktisix (Pentacon Six) medium format camera.
• Both share the same optical design, but the 120 mm could be described as a supersized version. Interestingly, the 120 mm made it to market a bit before the 80 mm version.
• At 120 mm, the Biometar sits nicely between the 80 mm standard lens and the 180 mm regular portrait lens.
Versions
During the 30+ years of construction, the 120 mm Biometar for the Pentacon Six mount saw the typical cosmetic changes (from silver with leather band, through zebra designs to all-black designs), but very few optical changes. The only noteworthy development is the introduction of multi coating, coinciding6 with the move to all-black cosmetic designs.
History of Carl Zeiss Jena
There are few names in camera optics more illustrious than that of Carl Zeiss. The company was founded in the German town of Jena in 1846 by Carl Zeiß (hence: ‘Carl Zeiss Jena‘). During 1846–1945 there are few major developments in lens optics that the company was not involved in. Names that are even today well-known in optics – such as Planar (1896), Tessar (1902), Sonnar (1929), and Biotar (1939) (as well as many names that only optics-buffs know) – were the product of Zeiss’ first century of technological innovation.
After the Second World War Germany was divided into a Soviet zone (subsequently: East Germany) and the west-allied zones (subsequently: West Germany). While the Zeiss works resided in Jena (optics and glasses) and Dresden (cameras), which were in the Soviet sector, a contingent of Zeiss managers decided to move west and ended up setiting up shop in the small town of Oberkochen in the American sector under the name of Opton Optische Werke Oberkochen GmbH. As the relations between the former allied deteriorated and the split into East and West Germany became all the more real, the Oberkochen works changed their name first to Zeiss-Opton and later to Carl Zeiss.
What ensued was a lengthy international trademark dispute with both Zeiss’ (Jena and Oberkochen) laying claim to the name ‘Carl Zeiss’. The resulting stalemate – emblematic of the Cold War in its entirety – resulted in that Carl Zeiss Opton was allowed to use the name Carl Zeiss in the West, but had to use the Opton brand in the East bloc, whereas Carl Zeiss Jena was the only real Carl Zeiss as far as the east bloc was concerned, but could – mostly – not use the Carl Zeiss -name for exports to the West8. The fact remains however, that – starting in 1946 from a shared base – Jena and Oberkochen developed as two independent companies for more than 40 years. During the entire Cold War period, VEB Carl Zeiss Jena was seen by the country’s leadership both as a paragon of the East German technology industry and a showcase of the socialist/communist system as well as a major source of exports (and hence, western currencies). Within the centrally directed economy’s hierarchy, Carl Zeiss Jena therefore had a more prestigious role than other East German optics manufacturers (prominently Meyer-Optik Görlitz and, later, Pentacon), meaning that Carl Zeiss Jena received privileged access to tools and materiel (including the first computer in East Germany) and that its products were always considered the premium alternative.
After German reunification also Zeiss East and Zeiss West were united again, and have since again been at the undoubtable forefront of lens development. Even though it was manufactured after reunification, this lens sample harkens to the time of the cold-war and the East/West split.
History of the Biometar designs
You can find JAPB’s short account of the Biometar’s development (in English) here. Alternatively, you can read a highly detailed description on the origins and development of the Biometar in German at zeissikonveb.de.
Adapting
The Pentacon 6 mount offers a wide range of alternatives for adapting.
To use this lens natively, you will need a Pentacon 6 mount film body. In practical terms this means either a Praktisix or Pentacon Six medium format film camera or a Kiev 60/6C medium format film camera. While neither of these families of bodies were manufactured in their millions, they remain readily available, and even serviceable.
Thanks to the generous image circle Pentacon 6 lenses offer, and thanks to the copious flange focal distance (74,1 mm) of the Pentacon 6 system, this lens can be adapted to every full frame (and smaller) SLR, dSLR and mirrorless camera assuming a suitable adapter can be found or manufactured. Moreover, Pentacon 6 lenses are so uncomplicated that a simple ‘dumb adapter’ will do the job perfectly.
Thanks to the generous image circle, Pentacon 6 lenses have also long been a strong candidate to be used on smaller formats (full frame and smaller) in conjunction with tilt/shift adapters. Alternatively, one can choose to daisy-chain adapters (e.g. Pentacon 6->Canon EF; Canon EF –> mirrorless) which not only broadens the range of available adapters, but also allows using speed boosters for those photographers that use smaller than full-frame sensors.
Finally, regarding larger than full frame, there are also options. Digital medium format is perfectly usable (assuming adapter availability) and many 6×4,5 film formats are likewise theoretical possibilities, but gaining functional adapters may necessitate some DIY.
Footnotes
- Focal length is (unless stated otherwise) given in absolute terms, and not in Full-frame equivalent. For an understanding of whether the lens is wide/tele, see ‘Angle-of-view’. ↩︎
- Picture angle is given in degrees (based on manufacturers’ specs) and concerns the diagonal picture angle. Rule of thumb (for 3:2 aspect ratios):
> 90 ° ==> Ultra-wide-angle
70–90 ° ==> Wide-angle
50–70 ° ==> Moderate wide-angle
40–50 ° ==> ‘Standard’ or ‘normal’ lens
20–40 ° ==> Short tele lens
10-20 ° ==> Tele lens
5-10 ° ==> Long tele lens
< 5 ° ==> Ultra-tele lens ↩︎ - Length is given from the mount flange to the front of lens at infinity. ↩︎
- Diameter excludes protrusions such as rabbit ears or stop-down levers. ↩︎
- S=straight; R=rounded; C=(almost)circular at all apertures. ↩︎
- I have never seen an all-black 120/2.8 Biometar that would not have ‘MC’ on its name ring, nor have I ever seen a zebra-variant that would have claimed multi coating or looked like it was. ↩︎
- Interestingly, it would seem that the black+leather band design was the only design used on 120 mm Biometar lenses that left the factory intended to be used on 35 mm film. ↩︎
- Online one can find many lengthy and heated disputes stating that only Jena/Oberkochen is the true Carl Zeiss. While many of these discussions are riddled with misconceptions and a poor grasp of facts and timings, they largely also tend to be tainted by ideologies. Those discussions that focus on claims of one or the other Zeiss not really having rights to using designs developed at pre-war Zeiss are especially ludicrous because after the war practically the entire patent catalogue of pre-war German patents was given freely to everyone (the allied saw this as a form of reparations), hence also kickstarting the Japanese optics industry’s ascendancy (the Japanese optics companies were the most avid users of German optics patents). ↩︎