Ersten wrote:
The Kenko 1.4x Teleplus Pro 300 teleconverter works on my T4i and my 70D, but not on my 7D Mark II. I get two error messages. One is Error 01, which says there is no communication between the lens and the camera, and to clean the contacts. The other error message says that the firmware update failed, and to try again. I spoke to Canon, and did not get a reason why this teleconverter won't work on the 7D Mark II. Also, there is no firmware update yet for this camera.
Most Canon EOS camera bodies are programmed to shut down auto focus if the calculated effective aperture for the lens and teleconverter is smaller than f/5.6, the Kenko TELEPLUS PRO 300 converters work the same way.