Data sheet: Jupiter-11

Pekka Buttler, 12/2024

Specifications

The table below summarizes the lens’ key specifications (measurements based on pictured lens):

Manufacturer:	KOMZ1	Lens name	Юпитер-11 / Jupiter-11 4/135
Focal length(s) 2	135 mm	Angle-of-view 3	18°30′
Maximum Aperture	f/4	In Production	1949–≈? (all variants)
Lens mounts (this lens)	M42	Other lens mounts	Contax/Kiev, Leica thread mount, Z39, Kiev Automat
Length 4	86,5 mm	Diameter 5	58,3 mm
Filter ring diameter	52 mm	Weight	391 grams
Lens element count	4	Lens group count	3
Aperture blades (S/R/C) 6	12 S	Focus throw	310 °
Minimum focusing distance	1 m7	Maximum magnification	1:5,3
Has manual aperture ring	YES	Has Manual focus ring	YES
Aperture mechanism type	Preset	Preset click stops 8	4•5.6•8-11-16-22

Further notes:
• The Jupiter-11 is a Soviet version of the Carl Zeiss Sonnar 135/4 (Introduced 1932). While the German original was produced only for Contax rangefinder cameras, the Jupiter-9 was produced both for the Soviet versions of the Contax (Kiev rangefinders) as well as Soviet versions of the Leica (FED & Zorki rangefinders).
• From the early 1960s versions for soviet SLRs (Z39 and M42) were introduced. Also a version (Юпитер-11 автомат) for the Kiev Automat mount was made..
• Importantly, the data in the table above applies to the pictured, relatively late variant. Rangefinder and earlier variants are mechanically significantly different and therefore differ in dimensions.
• The aperture is a preset aperture. The aperture ring is clickless, but the preset ring locks only on specific positions (See above).
• Because Soviet production of the Jupiter-11 started with parts taken as war reparations from Germany, the optical design was somewhat unstable in the early years. After the first few years, all parts were Soviet-built.
• The lens was single-coated from the onset, but at some stage in the 1960s multicoating was introduced.
• I have not managed to find conclusive information of when manufacture of the lens was ended.
• This, later era Jupiter-11 lens comes with a rather generous metallic lens hood, that moreover can be mounted reversed for easier storage.

History of Jupiter and other Soviet lenses

If you’re interested, I recommend you read JAPB’s article about the Soviet lens ‘business’.

History of the Sonnar designs

The Sonnar designs were originally born out of necessity. Back before the invention of lens coating technology, each air-glass boundary represented a serious problem. Every air-glass boundary meant roughly 5% of the light that would hit such a boundary would be bounced back, instead of passing through the boundary. This not only meant that each air-glass boundary would decrease the amount of light that passed through the lens to the film plane, a goodly portion of that reflected light was liable to be bounced around within the lens, leading to veiling flare and loss of contrast. Hence, design a lens to minimise the number of lens groups was crucially important.

Until the invention of the Sonnar design, the only ways to produce large aperture lenses were based on the double-Gauss (a.k.a. Planar) and Ernostar designs, both of which were hampered by that the number of air-glass boundaries were relatively high (a minimum of 8). The Ernostar was the 1924 creation of the young (then only 23 years old) lens designer Ludwig Bertele for the company Ernemann. At the time of its launch it was – at f/2 – the fastest still camera lens in existence, and one year later Bertele bested his previous record with the f/1.8 Ernostar.

After Carl Zeiss acquired Ernemann in 1926, Ludwig Bertele continued pushing the boundaries and the Sonnar was a further development of the Ernostar. Not only did the Sonnar in 1932 manage to achieve an even larger maximum aperture (at f/1.5), it did so while simultaneously decreasing the number of lens groups to 3 (hence decreasing the number of air-glass boundaries to 6). It seemed like the perfect solution.

Bertele developed a range of Sonnar-based designs: Standard lenses for rangefinder cameras (that did not necessitate a long back focal length) and tele lenses (for both rangefinders and SLRs). Some of those tele lenses were relatively ‘ordinary’ in their headline specifications (e.g. 135 mm f/4) but ahead of other contemporary lenses in their image quality, whereas other designs were clearly aimed at producing exceptionally bright tele lenses (such as the 85/2 or 180/2.8).

Versions

A considerable range of cosmetic and mechanical variants exist, but the fundamental optical design of the Jupiter-11 stayed unchanged throughout.

Adapting

This chapter will discuss adapting the (pictured) M42 mount version of the Jupiter-11.
If You’re interested in adapting an Z39 version, the best bet is to find a Z49-M42 adapter ring and use the lens as if it was an M42 lens.
If You’re interested in adapting a Contax/Kiev, Leica Thread Mount or Kiev Automat version, see the requisite JAPB article on the lens mount.

This lens cannot be used natively on any current SLR or dSLRs. To use it in its native environment, you will need an M42-mount film body. Luckily there are a lot of those still available.

Thanks to being a fully manual lens (manual aperture, manual focus), the lens can be adapted to all mirrorless cameras using a suitable adapter. Moreover, M42 lenses are so uncomplicated that a simple ‘dumb adapter’ will do the job perfectly. Due to the popularity of the mount, special adapters (helicoid adapters, tilt/shift adapters) are readily available. Alternatively, one can choose to daisy-chain adapters (e.g. M42->Canon EF; Canon EF –> mirrorless) which also opens up a wide range of speed boosters .

Using m42 lenses on dSLRs can also be an option, depending on which dSLR.
• Canon EF has the shortest flange focal distance among full-frame dSLR’s and Canon’s wide range of dSLRs are able to mount both M42 lenses perfectly using a simple adapter ring.
• Minolta / Sony A and Pentax K dSLRs are likewise able to mount M42 lenses using a simple adapter ring.
• Nikon F dSLRs have a long flange focal distance, meaning that mounting either M42 or Exakta lenses needs an adapter that uses corrective optics to allow anything close to infinity focus.

Footnotes

1. This lens was the bog-standard medium tele for the Soviet photographic industry but unlike other Soviet mass-produced lenses, this lens was manufactured almost only by KOMZ (Kazan Optical and Mechanical Plant). The Arsenal (Kiev) plant made the Jupiter-11 lenses for the Kiev Automat system. I have encountered accounts that the lens was also manufactured at KMZ, but have never seen a sample. ↩︎
2. 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’. ↩︎
3. Picture angle is given in degrees (based on manufacturers’ specs) and concerns the diagonal picture angle. Rule of thumb:
   > 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 ↩︎
4. Length is given from the mount flange to the front of lens at infinity. ↩︎
5. Diameter excludes protrusions such as rabbit ears or stop-down levers. ↩︎
6. S=straight; R=rounded; C=(almost)circular at all apertures. ↩︎
7. Please not that this rather short MFD is a characteristic of this, late version of the Jupiter-11 as rearlier and rangefinder models no not offer anything like this short MFD. ↩︎
8. Numbers equal aperture values on aperture ring; • intermediate click; – no intermediate click. ↩︎