This lens mount adapter allows Contax/Yashica (CY, RTS) to fit on a Canon EOS camera body.
Although the lens will fit physically, automatic diaphragm, auto-focusing, or any other functions will not operate correctly while using this adapter. In this case "stop-down mode" will need to be used when metering since the lens does not have the ability to have its aperture controlled by the camera body. You can shoot with manual mode or aperture priority mode with the EOS body. Infinity focusing is guaranteed.