Вот, например:
===
AF Mirror Adjustment Problem
After a thorough investigation, we have found that some EOS-1D Mark III cameras may have an issue with the mirror mechanism, which is part of the autofocus optical system. This issue may cause inconsistent focusing accuracy or inconsistent focus tracking with moving subjects when using AI-Servo AF and continuous shooting modes, particularly in high temperatures.
If the serial number on the bottom of the camera is between 501001 and 546561, it could be affected by the AF mirror adjustment problem, with the exception of cameras with the following serial numbers
(
Click Here) which were manufactured with an updated mirror mechanism. (Additionally, all EOS-1D Mark III cameras with serial numbers higher than 546561 have been manufactured with the updated mirror mechanism.)
===