Exposure compensation is a tool that every photographer ought to know how to use effectively. In this video, learn exactly how it works, when to use it, and how to use it.
Exposure compensation has seen an interesting shift over the last couple of decades. Its power over your photographs has typically been profound where your scene has high dynamic range and you don't want to lose details in your highlights, or the correct exposure of your subject would blow out the background and you're happy with that, but that camera's metering isn't. However, as the built-in light meter improved, so did the multitude of metering methods, and you could be forgiven for thinking that exposure compensation may become less relevant. That hasn't been the case.
One of the key reasons for this is that no matter how smart your camera becomes at metering, it's not outrunning the sensor performance in my experience. That is, the amounts you can manipulate raw files is growing, and so it often pays to underexpose your scene and then bring the levels up in post. So, for me at least, when a scene has high dynamic range, I'll use exposure compensation to underexpose the scene by a stop or two, knowing that I can bring parts back up to the correct exposure in post. Many photographers also use the auto ISO exposure compensation method Mike Smith details in this video.
So, if you're not certain how exposure compensation works or when you would use it, take ten minutes to learn it with this clear and concise tutorial.