In Part One, I explained some of the different types and nuances of various Contax lenses. So how do the Contax lenses fair compared to it's contemporaries? Let's look at the differences and similarities between Zeiss Contax compared with other Zeiss lenses both new and old: the Super Speeds, Classic (ZE/ZF.2) and CP.2s.
Through the seventies and eighties onwards, Zeiss had a range of cinema lenses called the 'Super High Speeds', known today simply as 'Super Speeds'. They were improved twice, from MkI (1975) through to MkII (1983) and MkIII (1995). The MkIs had an odd, nine bladed aperture that was arranged in such a way that it produced triangular bokeh. The MkIIs were massively improved mechanically (and some were optically improved too), and used a seven bladed aperture that produced a more pleasant, rounded-heptagon shaped bokeh. The MkIIIs were optically identical to their predecessors, though included geared iris rings plus much improved witness marks. The Super Speeds are T1.3 (f/1.2) throughout the range (the MkIs were T1.4), from 18mm to 85mm, and whilst the set differed slightly in focal lengths and speed to the Contax line, the similarities cannot be ignored. Both sets of lenses likely shared some design features and optical innovations, given that they were both cutting edge lenses for cine and stills photography at the time (and both began life in 1975). Both the Super Speeds and Contax lenses quite clearly have a slightly 'vintage' look to them when viewed wide open, though stopped down they both resolve extremely well, typical of the Zeiss namesake. What is interesting to note however, is that the 18mm Super Speed MkII and III shares an identical rubber grip on the lens barrel to the Contax lenses' focus rings.
If the Super Speeds are siblings to the Contax line, the Zeiss Classic (ZE and ZF.2) would be their descendants. The Contax line was discontinued and superseded by the ZE/ZF lenses in 2005, making use of newer and more popular lens mounts - Canon EF and Nikon F. The Contax line is so esteemed however, that many of the Classic lenses use very similar optical formulas and some actually share the same optics as their forebears. On those that do have identical glass, I dare say that only Zeiss' famous T* lens coating has been updated to improve veiling and control flare; distortion (of which there is essentially none), vignetting and sharpness are all pretty much the same.
The Zeiss CP.2s are another range of lenses we can compare and contrast with. As proper cine lenses, the CP.2s clearly have a mechanical advantage - they're all consistently sized, both their bodies and front diameter, they have geared focus and iris rings, accurate witness marks and long focus throws, all to aid users in a production environment. The aperture is now 14 bladed for a more circular iris and not only does the focus ring rotate in the correct direction, but the mount is interchangeable and available in PL, EF, F and E mounts too. However, the CP.2s are actually repurposed Classic lenses - meaning they share exactly the same glass. Some of the lenses are slower (ie T2.1) than their Classic or Contax counterparts, thought to limit the maximum aperture to a better performing stop. The 35, 50 and 85mm lenses however are available in 'Super Speed' variants which do not have this restriction, opening to T1.5 for an additional stop of light at the expense of resolution and increased vignetting. A representative from Zeiss has confirmed to me that the Standard and Super Speed CP.2s are in fact different lenses and not just the same albeit with a restricted aperture. This would suggest that the Super Speeds are the same as the Classic lenses and the Standards (of those with a 'Super' focal length) are different lenses. If we were to bench test and compare the CP.2s to the Classic lenses, we're unlikely to see any difference, other than the shape of the bokeh and possibly a difference in coating and therefore flare. The only other difference with the CP.2s compared to the Classics is that they're all colour matched and undergo an even more rigorous quality assurance process. Whilst perhaps not mechanically but certainly optically, the Contax range will hold their own equally as well against the CP.2s, despite essentially being their grandfather.
It all essentially comes down to whether you might want a lens that flares more, looks slightly more vintage and therefore exhibits a bit more 'character' than the modern counterparts - and of course the correct focus rotation and lower price are added bonuses! Zeiss are famous for their cool, clinically perfect look to their lenses - and the Contax lenses strike an excellent balance that provides both the crisp, sharp, punchy images you'd expect from a high performance lens and that gentle, pleasant personality found only on older glass.