I have been having focus problems with my SD870 IS. The problem is sporadic.

[smack53]

Of course, I assume the lens itself is clean and not smeared with fingerprints. Is there any specific time when the focus is giving you problems, such as lower light conditions, or close up shots?  Are you using a tripod when this occurs?

Sometimes the camera cannot find a focus if there is not a lot of contrast in the image you are trying to capture. These PowerShots use contrast detect for focusing, and if there is not enough, you may have to add lighting to allow the camera to pick up some contrast. If there is a focus assist beam in the camera, is it turned on? This could help to add just enough for the amount of contrast the camera needs.

Steve M.

[jbokansky]

Hi smack 53, Focus assist beam, described as "AF Focus" is on. The focus changes anytime a string of photos of the same lighting and subject are taken. Several shots will be OK and then the camera may be out-of focus.

[smack53]

When this happens, are you shooting at a still object or something in motion? Does the focus mode match what you are doing, such as focus tracking on for moving objects? Is the entire photo out of focus, or only a part of it? What kind of shutter speed is the camera using on the out of focus shots? Could be the shutter speed is very slow. What mode are you using to take the photos, ie, Auto, P, Scene modes, etc.?

Steve M.