The FC-chip currently does not support for Canon 5D Mark III, IV, or for Canon EF film cameras (film body cameras use electronics that do not support this type of adapter).
Note:
The focus confirmation chip does not auto focus or control the aperture on the lens being adapted.
This is a manual adapter, so lens functions that rely on electronic communication with the camera body (autofocus, AE metering, image stabilization, etc.) will be disrupted.
Set your exposure manually or meter using your camera's Aperture Priority (stop-down) mode.
If your lens does not have a manual aperture control ring, it will stop down to its smallest f/stop by default.