Data sheet: Yashica ML 28 mm f/2.8 (C/Y)

Pekka Buttler, 11/2024

Yashica ML 28 mm f/2.8 (Contax/Yashica mount) (this sample with some Schneideritis)

Specifications

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

Brand:YashicaLens nameML 28mm 1:2.8
Focal length(s)128 mmAngle-of-view275,4 °
Maximum Aperturef/2.8In Production1974–≈1996
Lens mountsContax/YashicaSubfamily (if applicable)––
Length341,8 mmDiameter461,2 mm
Filter ring diameter52 mmWeight233 grams
Lens element count7Lens group count6
Aperture blades (S/R/C)56 SFocus throw190 °
Minimum focusing distance30 cmsMaximum magnification1:8,6
Has manual aperture ringYESHas Manual focus ringYES
Aperture mechanism typeAutoAperture click stops 62.8-4-5.6-8-11-16

Further notes:
• In the Contax/Yashica era Yashica lenses were divided into three series:
• ML (abbreviation of Multi-Layer, in reference to coating technology). Yashica’s premium line of lenses. Designed and manufactured by Yashica.
• DSB (abbreviation unclear). Yashica’s budget line. Not premium coatings. Not designed or manufactured by Yashica.
• YUS (Yashica US). Yashica’s budget line for the Americas. Not premium coatings. Not designed or manufactured by Yashica.

• Throughout the life of the Contax/Yashica system, there was only on 28 mm prime offered under the Yashica brand (at the same time, two more 28 mm focal length lenses were offered under the Carl Zeiss brand for the Contax/Yashica system:
• 28 mm f/2 Distagon
• 28 mm f/2.8 Distagon [data sheet]
• Yashica lenses of this era are both outwardly and otherwise very similar to Carl Zeiss -branded lenses for the same system. Not only are many of the lenses outwardly very similar, they were very often produced at the same Yashica plant.
• At the same time, the Yashica brand was clearly intended to be the budget alternative in the Contax(Zeiss)/Yashica partnership.
• Yashica offered a series of square-formatted clamp-on lens hoods for its primes, but as they are very rare today, it seems they did not come supplied with the lenses. If you need a lens hood for your lens, you can try a generic 52 mm thread lens hood for standard lenses.

Versions

According to sources (brochures) there have been three versions of the Yashica ML 28 mm f/2.8 lens. The key details can be summarised as:

Versiontext on name ringoptical designMFD
IYASHICA LENS ML 28mm 1:2.8 YASHICA MADE IN JAPAN8 elements in 7 groups30 cms
II
YASHICA LENS ML 28mm 1:2.8 MADE IN JAPAN
7 elements in 6 groups30 cms
c
YASHICA LENS ML 28mm 1:2.8 c MADE IN JAPAN
5 elements in 5 groups23 cms

The first version was introduced in 1974 and seems to have been a quick-and-dirty conversion aiming to rehouse Yashica’s previous 28 mm f/2.8 lens in a new mount. It is quite rare on the 2nd hand market indicating a short production run.

The second version (pictured above) is the most common and was likely in production for a longish time.

The final (c for compact) seems to have been a relatively late entry, and I am not sure whether it was introduced to replace or complement the II -version. Also, there are some speculation that Yashica may have subcontracted the manufacture of these lenses to other Japanese manufacturers7

There is some confusion regarding whether the II-version really uses a 7 elements in 6 groups design, because even though this data is given by several official brochures, those same brochures invariably depict a lens schematic clearly showing 8 elements in 7 groups. Whether this means a typo in the specs or that the lens schematic is for the older version of the lens, I cannot say. What is however interesting is that this conflict is evident in several generations of brochures.

Adapting

This lens cannot be used natively on any current SLR or dSLRs. To use it in its native environment, you will need a Contax or Yashica body with a Contax/Yashica mount. Luckily these are quite easy to find, and Yashica’s manufacture of the electronics has been relatively resilient to the teeth of time. (The same cannot be said for the leatherette’s used on Contax/Yashica bodies, and the light seals quite often need fixing, but those are minor issues…)

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, a simple ‘dumb adapter’ will do the job perfectly. Thanks to the popularity of the C/Y mount, the availability of adapters to all mirrorless mounts can be taken for granted, on the other hand, specialist adapters (speed boosters, helicoid adapters, tilt/shift adapters) are not available for all mirrorless mounts, but daisy-chaining adapters (e.g. C/Y->Canon EF; Canon EF –> mirrorless) can offer a work-around.

Adapting C/Y mount 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 C/Y lenses perfectly using a simple adapter ring.
• Sony/Minolta A, Pentax K and Nikon F dSLRs are not able to use C/Y lenses without an adapter that uses corrective optics to allow infinity focus. However, such adapters are readily available.

History of the Contax/Yashica system

The Contax/Yashica system as well as the eponymous mount were co-designed by Zeiss and Yashica under the aegis of “Top Secret Project 130”. Zeiss’ intended contribution to the co-operation was the name ‘Contax’ as well as lens designs and the manufacturing of some of the lenses whereas Yashica would take care of camera manufacturing as well as some lens manufacturing. Moreover – beside the line of premium ‘Contax’ camera bodies and Carl Zeiss lenses, Yashica could also sell Yashica-branded bodies and lenses. This co-operation gave Yashica a leg up in competing with other Japanese Camera manufacturers while also allowing Zeiss access to the kind of economies of scale8 it needed and could not reach by itself.

The Contax (Contax/Yashica) system was unveiled at the Photokina fair in 1974 and the Contax RTS body hit shelves in 1975. While many German pundits thought it an outrage to produce anything named Contax outside of Germany, overall reception was very favourable. Not only would the new system be able to use Zeiss’ optics, also the new body design (especially the ergonomic for which the F. Porsche design studio had been engaged) seemed very promising.

The system was initially centred on aperture priority auto exposure, and the body-lens interface did not allow for the camera body to control aperture. To facilitate shutter priority and program auto, Yashica/Contax in 1984/5 unveiled the 159MM body (MM=multi-mode) and an upgrade to existing lenses so that they would support the full range of auto exposure modes in MM-capable bodies.

While somewhat successful, the the Zeiss-Yashica co-operation was by no means unproblematic. Yashica often felt Zeiss was unwilling to commit to sufficient volume (which likely contributed to production over time increasingly shifting to Japan). Moreover, although Contax/Yashica were at the forefront of the autofocus revolution (as evidenced by the functional prototype unveiled at fotokina 1982) Zeiss killed that development trajectory by claiming AF lenses could not be manufactured to Zeiss’ standards – a move that later led to Yashica’s breakaway AF system (see some details here) as well as the only serially manufactured in-body AF system in the 1996, Contax AX (touched upon here).

While the Contax / Yashica system technically stayed alive until replaced by the less successful Contax N autofocus system, it’s clear that as autofocus took the world by storm in the late 80s, early 90s, the Contax / Yashica system devolved into a niche / aficionado solution in the early 90s.

Footnotes

  1. 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’. ↩︎
  2. 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 ↩︎
  3. Length is given from the mount flange to the front of lens at infinity. ↩︎
  4. Diameter excludes protrusions such as rabbit ears or stop-down levers. ↩︎
  5. S=straight; R=rounded; C=(almost)circular at all apertures. ↩︎
  6. Numbers equal aperture values on aperture ring; • intermediate click; – no intermediate click. ↩︎
  7. Indicators point towards Cosina and/or Tokina. ↩︎
  8. ‘economies of scale’ is a business term signifying the phenomenon where manufacturing costs per unit fall when manufacturing numbers increase. Importantly, while almost all manufacturing industries have economies of scale, some industries have stronger economies of scale than others. Also, for economies of scale to be able to realise their effect, there needs to be a sufficient demand. ↩︎

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