Question about Pentax Optio S4 Digital Camera
I realized that if i take a medium-distance picture of a group of people (3), the camera will auto-focus to just one person (most likely the middle one), leaving the rest out-of-focus. This is also obvious if only 2 persons are in the picture. Do u experience this too? Or am i missing something?
Posted by Anonymous on
Acceptable focus depends on many things and an appreciation of aperture, lens, distance and shutterspeed is needed before understanding the finer points of 'depth of field' (what will and wont be in focus). Like all cameras, an auto focus camera cannot make everything sharp, it has to focus on one thing, usually in the middle, and the rest of the picture either falls in or out of focus, depending on the combination of the above points. For example, if you shoot on a wide-angle lens with a small aperture, say anything above f8, you should have everything you want in focus. In contrast, on a longer telephoto lens with a wide aperture (more light being allowed to hit the film or chip or whatever) the resulting picture will be sharp within only a few inches of the focus point. This can be really nice if you are shooting single portraits in bright light as the background will become extremely blurry and colourful. I am presuming that the shots you are concerned with had the camera settings set to wide aperture priority, possibly because it was dull or you had a 'sport mode' selected where fast shutterspeed is needed to catch rapid movement thus a wide aperture is needed to compensate and so shallow depth of field results. I don't know the camera you are using or whether you will understand any of the above. If you need a greater explanation of what is essentially a science, please let me know.
Posted on Sep 08, 2005
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