|Closest Focusing||0.6 m|
|Filter Size||58 mm|
|Diameter x Length||64.5 x 47.5 mm|
|Weight||305 gr (0.67 lb)|
Based on research it seems that I have the mkiii version as the lens has 1:1.8 instead of f1.8 on the two earlier versions. The Super Canomatic R lenses have a reputation for not aging as well as the FL and early FD models. My copy has some light haze but nothing major. The R lenses have two aperture rings--one to preset the aperture and the other to view depth of field. This is a neat feature of these lenses. The manual for R lenses state that all are SC coated, with the 50mm 1.8 having an amber coating (the 58mm 1.2 has magenta). The lens barrel has a DOF scale, distance scale, and infrared scale as one would expect. While the R mount will work on FL/FD bodies the reverse is not true. I now own 50mm f 1.8 lenses in R, FL, FD and nFD, and f1.4 in FL and nFD. The R version IQ is less sharp and color reproduction is more muted. Interestingly, at the moment they are often more expensive than the nFD f1.8. Unless one is collecting there is really no reason to own this lens as a shooter. It is built like a tank, however.