During the process of learning photography, everyone is destined to run up against this problem – blurry images. It’s commonly seen among photographers of all levels. But the reasons vary, blurry images may come in different ways and in different situations.
Among all the blurry photos, a big part them are caused by focus problem. During the past days before auto focus was invented, photographers needed to focus manually, this problem was not so common or we may say it obvious. Today most of the cameras are using electrical focusing system which seem sort of AI(artificial intelligence).
It brings us great convenience we have to admit that, but it’s not all powerful every time. When the camera focuses on a point (e.g. a tree behind a boy) that it “thinks” to be the subject, and pushes the button then a photo pops out with a clear tree and a blurry boy. If your subject is the boy, that is surely a blurry problem.
When the depth of field is too shallow for the subject, the pictures would also be blurry. These focus problems have very few solutions. However, depending on the types of cameras the solutions may vary a little. If you have a SLR camera, you got a few more options for correcting focus than those with P&S cameras.
A camera’s steadiness is not equal to your idea of holding the camera steady.
For example, in most cases you are sure to be as steady as a rock, but technically speaking, you are not. I mean, at least your heart is beating all the time. You can’t feel it doesn’t mean your camera feels the same way.
Actually cameras are sensitive to any vibration and blur has levels, strictly all the photos taken just with the support of hand holding are blurry, only your eyes cannot perceive. But here of course we only talk about those which our eyes can perceive. So let’s sum it up with several reasons: holding the camera incorrectly, common technique errors (e.g. too long shutter time), and unstable support.
This kind of problem is usually easier than those above to fix. You just need to reduce the shutter duration and what’s more, make sure there’s enough light. Therefore you can enlarge the aperture in addition to raise up the sensitivity (iso). For example you are taking a photo for a little boy.
When he starts to run, you need to change the setting combination with higher shutter speed and relevant larger aperture than when he sits still playing with his little toys.
Dirt on the lens
Take good care of your cameras and the periodic maintenance job. Clean the lens with the piece of cloth attached. Do not take off the lens frequently if not required (for SLR owner), this will expose the inner parts and easy to get dust. And dust on CCD/CMOS or the inner side of the lens glass will be much more complicated.