Use the Histogram as a Guide during Postprocessing
A photo’s histogram is a graphical representation of the tones in the image. The left side of the graph represents the darkest blacks in your image, and the right side represents the brightest whites.
There’s no right way to postprocess an image. In fact, your individual workflow for adjusting your image’s tone may be a very different process, but if you need some guidance to get going, these are the steps you can take when adjusting the tone of your images.
Before you start adjusting your image’s tone, make sure you’ve finished adjusting your white balance. Under the Develop Module in Lightroom, click the Basic panel to reveal your tonal controls.
Here is a well-balanced histogram that spans the entire range of the graph and falls off on either end, like a gradually sloped mountain. The histogram of an underexposed photo is bunched up near the left end of the graph, and the histogram of an overexposed photo is bunched up near the right end of the graph.
Whenever you adjust your tonal controls, keep in mind that you should strive for a well-balanced, properly exposed histogram and use its appearance as a guide.
Look at your image and its histogram to determine whether it’s underexposed or overexposed.
If it’s underexposed, move the Exposure slider to the right while keeping an eye on your histogram. If it’s overexposed, move the Exposure slider to the left while keeping an eye on your histogram. In either case, continue moving the slider until your histogram stretches out and spans most of the graph.
If you have to brighten up your image, you may need to recover some of your highlights (the lightest areas of your photo) if they’ve been blown out.
Look at your image to determine whether your highlights have lost a lot of detail. Also look at your histogram as a guide; if your graph has a tall spike at the right-hand end, you need to use the Recovery control. Just slowly move the Recovery slider to the right until the spike on your histogram comes down. If your highlights aren’t blown, skip this step.
Look at your image again and determine whether you need to use the Fill Light control.
If your shadowed areas seem too dark and you want to regain some detail in them, slowly move the Fill Light slider to the right. You can also assess this need by looking at the histogram. If the middle peak of your histogram mountain is still hanging out on the left-hand side of your graph, try adding some fill light.
The histogram’s peak should slowly shift more toward the graph’s middle. Don’t go overboard with this tool — a little goes a long way!
Again, look back to your image; if you don’t see a nice, rich, deep black anywhere in your image, it’s time to increase your blacks.
Your histogram can also clue you in here. If the histogram doesn’t reach all the way to the left-hand side of your graph, your photo likely lacks those deep blacks. Move the Blacks slider to the right while keeping an eye on your image and your histogram.
Watch as your histogram shifts to the left-hand side of your graph. Keep going until the histogram hits, or even slightly spikes up, the left-hand side of the graph.
Next, assess your brightness and contrast.
You really only need to adjust the brightness if, overall, your image still seems too light or dark and your histogram still appears slightly bunched on the left- or right-hand side of your graph.
Move the Brightness slider to the right to make your image lighter; your histogram also shifts to the right. Move the Brightness slider to the left to make your image darker; your histogram also shifts to the left.
If your image can still use some more pop, try adding some contrast to it.
Move the Contrast slider to the right to add contrast and to the left to decrease contrast. Notice that when you add contrast, your histogram spreads out to either end of the graph, making it look more like a plateau than a mountain (oh, the highs and lows of photography . . . ). Shown here is a before-and-after comparison of adjusting tone.