The lens has no AF sensing at all, so cannot control the camera, it can only transmit light to the camera AF sensor. Now it seems that is sufficient for Standard AF, but not on older cameras for AI Servo. From what I have read, the problem seems to be in light of low contrast. Now if all cameras are affected, in all situations then that is a different matter, but a lot of people have posted fine pictures using more recent Canon cameras and have reported no problems. At the moment there is not enough data from owners of more recent Canon cameras, to know if it a more general problem.
Mike Engles
Mar 08, 2014 at 06:19 AM
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