Editing Raw Files: clipping warnings
Assess the effects of your edits by enabling the preview and clipping warnings. Clipping isn’t always easy to spot, but ACR gives you a way to see exactly where it’s occurring.
If the histogram suggests its presence, you can activate a display that shows where pixels are being clipped.
Click the small triangle at the top-left of the histogram or press U (for ‘underexposed’) to display clipped shadows in blue, and click the triangle at the top-right or press O (for ‘overexposed’) to display clipped highlights in red.
You can also view where pixels are being clipped, and in which colour channels, if you hold down [Alt]/[Option] as you move Adobe Camera Raw’s key tonal sliders, Exposure, Recovery and Blacks.
Can I get more accurate clipping warnings?
How do you get more accurate clipping warnings? The red highlights warning appears if any one of the red, green or blue colour channels is clipped, while the blue shadows warning appears only if all three channels are clipped.
This won’t matter in practice for many images but, as we’ve mentioned, clipped highlights are considered less palatable than clipped shadows, and the more precise warning might help you recover the maximum amount of highlight detail.
Is all clipped shadow detail really lost?
When you open a RAW file that contains underexposed areas, you’ll often find that you can recover detail from shadow areas even though pixels have a value of 0 for all three colour channels, and so appear pure black.
This is because it’s Adobe Camera Raw’s default Blacks adjustment of 5 that’s causing those areas to be clipped. If you reduce the Blacks setting for such images, you’ll find there is in fact some colour and detail hidden in the shadows.