“As I mentioned when I talked about ND Grad Filters, the human eye can capture huge differences in brightness from the reflection of the sun on a rain-soaked road to the darkness of the ground under the shadow of a tree – and all at the same time. A camera is nowhere near as good, only being able to resolve a few stops of light (remember that a one-stop increase in exposure equates to double the amount of light, so 2 stops is 4 times the light, 3 stops is 8 times and so on). This means that the brightest and darkest things in your picture don’t want to be more than a few stops apart. “
I don’t know about you, but that explains a lot to me about why my photos never seemed to come out quite right, and why they almost never come out the way I see them myself.
Trust me on this one, it’s a great guide, and I highly recommend you read it if you have any interest at all in exploring digital photography (even if you aren’t using a Digital SLR camera, like he is).