Today’s Question: When do you use a histogram?
Tim’s Quick Answer: I use a histogram when reviewing photos on my camera’s LCD display to get a better sense of the overall exposure. Once I’ve downloaded my photos to my computer, however, I rarely use the histogram because I prefer to make use of the clipping preview display instead.
More Detail: A histogram can certainly be helpful in evaluating the overall exposure for a photo. In particular, I recommend using a color (RGB) histogram, where each color channel is shown individually, so you’ll know when just one or two channels are clipping rather than only seeing clipping once it has affected all three channels.
However, I don’t use a histogram very often. On my camera’s LCD if I want to evaluate the exposure of an image, I’ll use the histogram display for that evaluation. This allows me to get a much better sense of the exposure than if I only looked at the image preview, or if I relied solely on the “blinkies” clipping warning that is available with many cameras.
Beyond the camera, I almost never review the histogram. That is mostly because I use a clipping preview instead of a histogram when evaluating the highlight and shadow details for a photo.
For example, in the Develop module of Lightroom Classic (or in Adobe Camera Raw) you can hold the Alt/Option key while adjusting Exposure, Whites, and Blacks (among some of the other tonal adjustments). This provides a detailed clipping preview so you can determine the point at which detail is lost on one or more channels.
With this helpful and detailed clipping preview display, I simply don’t generally find any reason to reference the histogram at all during post-capture processing. But again, the histogram can be very helpful in the context of evaluating exposure for photos on your camera’s LCD display.