What are histograms and do I really need to check them?
A histogram is a graphical representation of the pixel values in a digital image. The most important use of your camera histogram is to check your exposure. In simple terms, if your histogram touches or extends past the left edge of the graph, your image is underexposed. Conversely, if your histogram touches or extends past the right edge of the graph, your image is overexposed. Depending on scene content, you may have more of your graph to the left (darker pixels) or more to the right (lighter pixels), but as long as it stays between the end lines of the graph, your exposure is good.
