Update: Canon has offered the following official response: “Canon has become aware of this phenomenon, which occurs when focusing on a close subject at 200mm,
and is preparing a firmware update that will be released as quickly as possible.”
Canon may have an issue on its hands as multiple users of its new RF 70-200mm F2.8 L IS USM lens report that it misses focus when used at the closest minimum distance. A thread on our forums as well as posts on Fred Miranda state that when used at the longer focal lengths, and with subjects at the closest focusing point, the lens focuses in front of the area under the AF point in use.
Tests carried out by users report the fault is most pronounced at the longer ends of the focal range and that it gradually reduces as the lens is brought back to the 70mm setting. More distant subjects also avoid any issues, as it seems to happen only close up.
The Canon RF 70-200mm F2.8 is said by owners to be exceptional in every other situation, but this will be something that needs attention. Forum member pokesfan says that his lens was sent to Canon to be checked and the service engineers claimed there was nothing wrong with it.
Source: dpreview.com
