If you have a reasonably new camera, it should have a metering mode called “evaluative”. Make sure you have your meter set on this mode and fire away with confidence as long as you are not in a tricky lighting situation- more about tricky situations in a minute.The evaluative mode takes in the whole scene and then determines proper exposure based on a careful evaluation of all the shading and tones present. Generally speaking, you’ll get great results from today's sophisticated meters.

Exposure problems stem from lighting situations, which “trick” your camera into over or underexposing the film. For Example,if you’re shooting toward a beautiful sunset, your meter reading will be dominated by the sun and cause the photo to be underexposed.

Using spot metering modes or center-weighted modes causes your photos to come out “middle tone” which is ok unless you’re shooting bright white snow or bright colors. Who wants gray snow? Not me. So you have to know enough about exposure in these situations to compensate OR you can simply CHEAT.

How to Cheat? Simple, if you think you might be in a tricky exposure situation just take one photo at the exposure recommended by your camera’s meter. Then take another shot at one stop above and one stop below the exposure recommended by your camera meter. One of those exposures will likely be good. This process is a time honored way of making sure you get the exposure right when you really want to get that photo. It’s called bracketing, and most pros use it whenever needed .

Of course bracketing uses a lot of time and film.If you want to really understand, the ins and outs of exposure there are many good books around- one of the most detailed is Nature photography-by John Shaw.This is my favorite because he assumes you know absolutely nothing and that you want to know absolutely everything.