Before the rush

Before the rush
by evan-pak

Submit your Photo
Hall of Fame

Please participate in Meta
and help us grow.

Photography Stack Exchange is a question and answer site for professional, enthusiast and amateur photographers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I'm using a Canon SX210IS and I encountered the following problem:

When I shoot movie in HD, the camera every few seconds gets out of focus and back into focus.

This lead to a bad quality movie and it seems like I played with the zoom button in an out all the time, when in fact I didn't touch at all.

Any ideas?

share|improve this question

That would probably be the contrast-detection autofocus. Unlike the advanced phase-shift detection autofocus normally used for still shot AF in DSLRs, contrast-detection AF has to do a bit of "hunting" to find the point of highest contrast.

The use of contrast AF is actually not limited to point and shoot cameras, it is also used in DSLRs when using a live view mode. So as long as you are actively focusing, there is probably nothing you can do to prevent momentary focus hunting like that (I checked the manual, and there did not seem to be anything about AF during video that might help.)

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.