When you take pictures you probably do what I do and hope that your smart camera has done all the legwork for you. Most of the time it does but sometimes, especially for those tricky lighting compositions, a little insurance is wanted so you aren’t cursing a shot that turned out too dark or too bright after you brought it home and loaded it in your computer. If you have something like photoshop and shoot in RAW, you don’t have to really worry as exposure can be manipulated pretty much how you want it without photo degradation. For you JPEG shooters who don’t want to spend a ton of time in post here is what you do to optimize your lighting experience: Check the histogram. Now I won’t go into a detailed explanation of this graph but to say that it is an indicator that tells you how much visible light is in your picture. Visible light is the range from so dark no detail is present to so bright that details are pure white. Here’s a visual sample of the effects different exposures have on a histogram:
As you can see, the darker picture shows the histogram detail shifted to the left (the darker range) while the lightest picture is shooting off the right side of the graph area (the lighter range) As you move from left to right along the graph the details of your picture will appear darker to brighter. Your sweet spot for the most detail is generally in the center of the graph.
Most DSLR cameras have the ability to show a histogram preview of your picture. So if you are shooting a scene like the one above and want to get the most detail out of it, you may want to manually adjust your camera’s exposure so that your histogram has as much detail (peaks) toward the center of the graph. Now, it’s not necessary to always get your histogram centered. Below is an HDR image. This wouldn’t be possible right out of your camera, but it’s to illustrate what a detailed picture looks like in a histogram.
This tip is mostly helpful for landscapes or well-lit people shots. Sometimes you want darker, like a night shot of a candle, or brighter, like an artful sun-flare behind a tree.