Rayqual Contax / Yashica Lens to Canon EOS Camera Body Lens Adapter

There has been some internet discussion claiming it is best to use different thickness Contax/EOS adapters for different Contax/Yashica lenses.  While I admit I have no proof to the contrary, I have to say personally I find such a claim impossible to believe.   I don't believe ANY lens maker, especially Zeiss, would design  lenses within the same lens line with a different back focus, beyond their normal manufacturing tolerances.   However don't take my word on this, just email the good folks at Zeiss.com to get it from the horse's mouth.

Contax/Yashica lenses were discontinued January 2005 once Kyocera and Zeiss dissolved their partnership and discontinued the entire Contax lineup.   Prices started going up on the harder to find lenses, especially the ultra wides, in big part because EOS shooters became dissatisfied with Canon ultra wide lens performance. 

LENSES WHICH WILL NOT WORK: Reportedly the following adapted Contax lenses are not compatible with the EOS 5D: 18/4, 85/1.2, and 135/2.  There have been conflicting OK/Not OK reports on the Contax 28/2.8, perhaps suggesting unreported lens variations.  Lens mount variations have been reported on the 28/2.8 MM and the 35-70 MM lenses.  These lenses may require about 1mm to be filed from the end of the brass locking latch,  before the lenses will lock on the adapter.  Take note that if you do this modification, the adapter may or may not lock on other Contax lenses.

The Canon 5D series has a larger than normal EOS mirror, so take extra care mounting lenses.  This list is not represented as complete.  If you find other Contax mount lenses which will not mount safely on the EOS adapters, let me know and I will add to this list.

AN ALTERNATIVE METHOD ON LATER CANON DSLRS
IS TO LOCK THE MIRROR UP AND SHOOT LIVE VIEW!