Using the Histogram to get the best exposure
Y our DSLR has a very powerful exposure meter on it, but it also has a useful feature to go beyond simple metering. When you review a photo on you screen and you press INFO it should show a histogram similar to the image at the top. In the case of Canon camera, the more to the left the darker the image, the more to right the lighter the image. This eliminates any errors or failure of the rear screen viewer to render the image properly, particularly in difficult to view lighting. To do so, take a test photo of your subject and look at the histogram. Now if it is too dark, adjust exposure compensation a click or two brighter and take another, review the histogram. The intent is to just get the right most area of the graph just at, but not against the right limit. The example at the right above for Bright Image shows too much bright, that is, information in your photo is be bleached out, and no amount of post-processing can fix it. On the other hand, the Dark Image sample could