Bad exposure (image is overexposed). And how to prevent it? The question is, what do you take pictures with - some cameras have a real-time histogram and a fully manual exposure mode. Other cameras (typically automata) do not have a histogram (so you won't know the potential overshoot in advance) or a manual exposure compensation mode. In the first case, all you have to do is learn how to operate the camera. In the second case, holt, you have to learn to take pictures - for example, digitals can't take pictures of big differences in lighting (they don't have as much dynamic range as analogues), so you have to learn to choose a scene so that they aren't ... Correction can help you to some extent exposure (EV) - this allows you to cancel overshoots at the cost of underexposing darker parts of the subject (which can then be corrected when processing the photo on a computer).