Exposure Compensation

All DSLR cameras and many point and shoot style cameras are capable of exposure compensation, so what is it, when do you need it, and how do you do it. Well, I'll try to answer those questions here and maybe come up with an assignment you can try.

When you take a photo in any of the camera's automatic modes the cameras computer decides how bright your picture will be. The photo here was taken in a dark bar and the lights were my subject. The automatic shot looked nothing like this. My camera's computer did what it is supposed to do. It showed me a not very attractive old bar. The room was dark and the lights were interesting and it looked very different to me than it did to my camera, so using "Exposure Compensation" I underexposed the shot by 2 stops and got what you see here, a photo that looked like the room looked to me when I took the photo. Anytime the image you see on your camera's LCD looks brighter or darker than either "real life" or the image you had in your head, it's time to compensate.

How do you do it? The scary advice is "Look in you Camera Manual". If your manual has an index in the back look up "exposure compensation", or just look at your camera. You're looking for a button like the one shown on the Nikon (right) that shows a [+/-]. If you have such a button, hold it down and rotate the command dial. One direction will give you [+] numbers and the other will show [-] numbers. The numbers will likely either jump in half-stops or third-stops. The display will show [0.0] when you press the button and when the command dial is turned in the camera's plus direction it will change to [+0.3] and a photo taken now will be 1/3 of a stop brighter than before. Most cameras will allow up to [+2.0] and down to [-2.0] some may go to plus or minus three.

Now you have control over how bright your picture will be! Place your favorite subject against a bright sky and back up so that there is quite a bit of sky showing. Take a shot and look at it on your LCD. Your subject is probably a little dark so let's make it worse. Move your exposure control in a minus direction to [-2.0] and take another shot; see if you've created a silhouette. Not actually worse, just different. Now move the exposure in a positive direction; try [+1.0] and also [+2.0]. One of these will probably brighten your subject and make them look correctly exposed. If the change looks to heavy-handed remember you have those in between 1/2 or 1/3 stop positions.
I hope this gives you a tool and helps you get a photo you like better than the automatic one. Camera computers get better and better, but they will never know what you want so take control and keep shooting.