In the base of the mirror box below the mirror is the autofocus arrays, each array has a fairly small access hole that can get dust/fluff/hairs in them,
Carefull lift the mirror clear (or set mirror lockup and press the shutter) and blow out the offending af array hole with a bulb blower (or a lens puffer brush with the brush removed, I definitely would NOT use canned air)
Watch out for the mirror lockup timout as you don't want the mirror slapping down onto the blower nozzle.
Discussion
1 repliesOne of the auto focus points seems to have stopped working on my 20D, has anyone else had this with a Canon, can it be easily fixed?
Thanks
Gavin
In the base of the mirror box below the mirror is the autofocus arrays, each array has a fairly small access hole that can get dust/fluff/hairs in them,
Carefull lift the mirror clear (or set mirror lockup and press the shutter) and blow out the offending af array hole with a bulb blower (or a lens puffer brush with the brush removed, I definitely would NOT use canned air)
Watch out for the mirror lockup timout as you don't want the mirror slapping down onto the blower nozzle.
Good luck and be careful.
Kev