My wife and I both bought the same straight talk phone, ZTE Savvy with 4.1, and our two phones focus differently and I can't find a setting for this. On the phone that does focus correctly, when I open the default camera app and point at different objects near and far it appears to slightly 'zoom' and the image becomes clear. On the other phone it doesn't do anything, the lighting adjustment occurs but no focus adjustment.
I read that some people just download different camera apps, but the main problem is that we need to use our bank's app to deposit checks and the focusing behavior is the same in that app. The phone that doesn't focus will not take a clear close up of a check.