Here is something I've learned from beta reading Dan Margulis' Professional Photoshop, 5th edition (due for publication in the fall of 2006). Consider it a teaser.
Steps to tune Shadow/Highlight parameters:
- Set Amount to 100%, Radius to 3%
- Tune Tonal Width to target the adjustment to the relevant areas of the image.
- Tune Radius to bring out the details in that area.
- Tune Amount to make it look good.
Not very different from the steps to tune USM, really.
Now I'll walk though these steps to bring out the highlights using this image by Sid. (Shadows are completely analogous and are left as an exercise for the reader.)
Amount to 100%, Radius to 3% The dialog looks like this. Notice that I have the two sliders on the bottom, Color Correction and Midtone Contrast set to 0. If you know anything at all about adding pop to images, the best practice to to set these to 0 and then add adjust contrast and color yourself after the shadow/highlight adjustment.
Tune Radius to Bring Out the Details This parameter controls the transitions between areas more and less impacted by the adjustment. For those familiar with HIRALOAM sharpening, it's very similar to tuning the Radius in that technique. We want to find a value that best brings out shape in the targeted areas. Too low a value, and the highlights are blurred into a solid (as at the end of the last step). Too high a value, and the the transitions are so sharp that fine shape detail is lost. Here is the image with Radius set to 100.
Tune Amount to Make it Look Good Now it only remains to decide just how much of a good thing you want. The Amount slider determines the opacity of the adjustment. Set to 0, the adjustment does nothing. Set to 100%, it does as much as it can, which is rarely what you want (unless you plan to use in some sort of a blend in subsequent steps.) This is a matter of personal taste, but I ended up liking 23%.
HHere is the Shadow/Highlight dialog box at the end of tuning the highlight adjustment.
At this point consider the other half (shadows) of the adjustment to bring out shadow details. The steps are exactly the same. After that, you can add pop and sharpness with your favorite workflow. Most likely you'll want to add some saturation or LAB steepness (not quite the same thing) now that you have better contrast.
Important: If you are starting from a RAW image, make sure you to tune the Exposure and Shadow amounts in ACR to minimize clipping. Checking the Shadow and Highlight checkboxes at the top right of the ACR window will make areas with clipping obvious.
To view an animated before/after, click here.
To discuss this technique, visit digitalgrin.com.