Originally posted by stevebrot The part I don't get is that the lag is after AF lock. Let me get the camera and see whether I can get it to do this.
I missed that part. Does not seem that it could be the camera going to sleep then, it is not going to focus until after it wakes up.
- 2 second delay (or other non-SR mode) with the shooting mode set to not save on shut off
- defective shutter button
- user is not keeping the shutter button down enough to maintain the AF lock
- AF-C mode with focus priority set and focus lost momentarily during a pan
- sleep mode and the OP just thought it was focusing
- some kind of weird lens interaction - dirty contacts
None of those sound particularly likely given the information supplied.
OP - can you try setting the auto focus to the AF button on the rear and testing it that way? It is under button customization. In this mode the autofocus is controlled by the back AF button and all the shutter button does is trigger the shutter release. Might help diagnose the issue.
You could also try turning the timer for sleep mode completely off to see if that makes any difference.