« on: June 01, 2013, 08:36:32 PM »
It depends. My 5D3 body did not need any afma for all my five l lenses. Recently I had to send in the body to canon service for a sensor change. After the sensor change the afma drifted to about +5 to +8. I contacted canon about it and they asked me to resend it in for focus calibration. Some accident happened during the af adjustment procedure at canon and they burnt the board (the tech told me that the af was on for too long during testing). I received the new body and after checking the af, it did not need any afma at all for all five lenses.
So, it seems that new 5D3 bodies with factory settings seems to not require any afma. However, the local canon service center may not have the same factory equipment for sensor af adjustment, and the af calibration may not be 100% correlated to the factory equipment. Therefore if any sensor change/reassembly is done at the service center, it may require some afma.