Do not discount the Kiron lenses totally and especially out of hand. While I will agree that they may not be the equal of the best that Carl Zeiss could do, Kino Precision produced many lenses that are considered superb. They made the LESTER-A.-DINE 105mm f/2.8 MACRO 1:1 lens which is still regarded as one of the best 1:1 macro lenses that you can find for many of the manually focusing cameras out there. It was originally marketed as a medical imaging lens. While I do not have very many Kiron lenses, those that are here have performed very well, and they are certainly in the same ballpark as my Canon, Minolta, Nikon, and Asahi-Pentax lenses.
And, Kiron lenses in the Contax mount are not at all common. This is the first time that I have actually heard of someone having them.
You know, just above, i made a subjective evaluation. I will put them on the lens test bench and come up with some numbers to actually see what mine are doing.
And, while I am here on this subject, may I also ask how many other "evaluators" out there actually have the equipment or an objective method for testing the lenses about which they are commenting? While I may agree that my question may be a bit harsh, I also point out that simply declaring that any maker's lenses are "worthless" without having any objective data to back up and support such a claim may be totally unwarranted. Even if the comment is mainly about the state of the market prices, even that does not agree with the fact that Kiron lenses tend to run in the same league as the Vivitar Series One and the Tamron Super Performance lenses as far as pricing is concerned. Referring back to the lens tests published in MODERN PHOTOGRAPHY, POPULAR PHOTOGRAPHY, and others, will show that these lenses did run right with the OEM lenses, and often even bettered the OEM lens performance.