Pekka Buttler, 01/2023
Specifications
The table below summarizes the lens’ key specifications (Measurements based on pictured sample):
| Brand: | Minolta | Lens name | MC W.Rokkor-SG 1:3.5 f=28mm |
| Focal length(s) 1 | 28 mm | Angle-of-view 2 | 75,4 ° |
| Maximum Aperture | f/3.5 | In Production | 1966–1968 |
| Lens mounts | Minolta SR | Subfamily (if applicable) | MC (I) |
| Length 3 | 50,5 mm | Diameter 4 | 70,0 mm |
| Filter ring diameter | 67 mm | Weight | 307 grams |
| Lens element count | 7 | Lens group count | 7 |
| Aperture blades (S/R/C) 5 | 6 S | Focus throw | 100 ° |
| Minimum focusing distance | 60 cms | Maximum magnification | 1:19,4 |
| Has manual aperture ring | YES | Has Manual focus ring | YES |
| Aperture mechanism type | Automatic | Aperture click stops 6 | 3.5-5.6•8•11•16 |
Further notes:
• When Minolta introduced the Auto W.Rokkor- SG 28 mm f/3.5 (this lens’ direct predecessor) lens in 1963, it was the widest-angle regular lens for the Minolta SR (the preceding 21 mm lenses invade the mirror box and necessitate mirror lock-up and a separate viewfinder). The Minolta user base would have to wait until 1971 for a wider regular lens (the non-invasive 21 mm f/2.8) to be introduced.
• There are two MC I variants of the Minolta 28 mm f/3.5. This (1966–1968) version sporting a 67 mm filter ring diameter, and a later (1968–1970) version sporting the regular 55 mm filter ring diameter.
• Alike many early Minolta lenses, this lens has a small aperture stop down lever for use on cameras that lacked the requisite control.
• The original Minolta D70KA 70 mm lens hood is a rectangular, clamp-on model, that commands a specialty item price. Problematically, generic 67 mm thread wide-angle lens hoods are not exactly common.
Versions
The ‘slow’ (f/3.5) 28 mm lens was present in the Minolta lens lineup from 1963 until the end of the Minolta SR system. During that time, it went through several iterations, and while many of these mostly reflected cosmetic and lens-body interface changes, the optical recipe was also changed twice. The table below shows the genealogy of all Minolta SR 28 mm f/3.5 lenses:
| Name (on lens) | Variant & Generation | years | focal length | max. aperture | min. aperture | elements | groups | filter thread | weight |
| AUTO W.ROKKOR-SG | AR II | 1963–1966 | 28 | f/3.5 | f/16 | 7 | 7 | 67 | 345 |
| MC W.ROKKOR-SG | MC I | 1966–1968 | 28 | f/3.5 | f/16 | 7 | 7 | 67 | 350 |
| MC W.ROKKOR-SG | MC I | 1968–1970 | 28 | f/3.5 | f/16 | 7 | 7 | 55 | 245 |
| MC W.ROKKOR-SG | MC II | 1970–1973 | 28 | f/3.5 | f/16 | 7 | 7 | 55 | 245 |
| MC W.ROKKOR(-SG) | MC X | 1973–1975 | 28 | f/3.5 | f/16 | 7 | 7 | 55 | 260 |
| MC MINOLTA CELTIC | MC Celtic | 1974–1977 | 28 | f/3.5 | f/16 | 7 | 7 | 55 | 260 |
| MC W.ROKKOR | MC-X | 1975–1977 | 28 | f/3.5 | f/16 | 5 | 5 | 55 | 220 |
| MD W.ROKKOR | MD I | 1977–1978 | 28 | f/3.5 | f/22 | 5 | 5 | 55 | 195 |
| MD W.ROKKOR | MD II | 1978–1981 | 28 | f/3.5 | f/22 | 5 | 5 | 49 | 160 |
| MD | MD III | 1981-≈1985 | 28 | f/3.5 | f/22 | 5 | 5 | 49 | 170 |
Adapting
This lens cannot be used natively on any current SLR or dSLRs. To use it in its native environment, you will need a Minolta SR (SR/MC/MD/X-600) film camera. Luckily these are quite easy to find. To use the lens’ full designed capabilities, a Minolta MD-compatible body (any Minolta SR body launched after 1977) is most recommended..
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 Minolta SR 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. Minolta SR -> Canon EF; Canon EF –> mirrorless) can offer a work-around.
Using Minolta SR mount lenses on dSLRs is also be an option, but it is not trouble-free due to that the Minolta SR mount’s flange focal distance is shorter than that of any dSLR mount (technically with the exception of Olympus’ four thirds mount). Hence, any attempt at adapting Minolta SR lenses must rely on an adapter that uses corrective optics to allow infinity focus. However, such adapters are readily available.
History of Minolta
Minolta exited the camera business in 2006 and sold its remaining photographic assets to Sony. The 50 years before that ignominious date tell a very different story: one of a Japanese optics and innovation powerhouse that has interesting links to Germany – not Nazi Germany, but both pre WWII Germany as well as postwar West Germany. Read more in the Minolta company profile.
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:
> 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. ↩︎
- Numbers equal aperture values on aperture ring; • intermediate click; – no intermediate click. ↩︎