I have a sony HDR SR7E camcorder,I notice that as i film it goes very slightly in and out of focus?

Question

This does not happen everytime but it is very annoying when it does.Can anyone tell me what the problem is? The camera is only 3 months old.

Answer 1

this focus hunting is a natural result in any autofocus camera. focus is more critical in high def pictures therefor more noticable.  the mpeg2 compression used in high def recording make the problem worse because instead just one out of focus frame, the problem will be replicated in 4 or 5 subsequent interpolated frames.

this is why professional video is alway shot in manual focus mode.