I’m a big proponent of using non-destructive techniques in a digital enhancement workflow. Among other things it means being able to change your mind at a latter date and to be able to modify or even completely remove an edit. In CS4 Shadow/Highlight can be applied to an image as a Smart Filter. And as a Smart Filter the tool’s dialog can be re-opened and changes applied at any time.
Here is the shooting metadata for this image:
Fuji S2 with 12-24mm at 17mm
1/2 sec @ f/22 ISO 100
Matrix, Aperture Priority, Comp 0
And here is the layers panel for this image showing Shadow/Highlight being applied as a Smart Filter.
As good as this advice is, that not the tip in the post. The tip is about using the Shadow Highlight command.
It used to drive me nuts, when I opened the S/H dialog the image would change dramatically. This was because the default settings apply a fair amount of shadow recovery. A work around that I discovered is to set both Shadow and Highlight Amount sliders to 0 and then Save As Defaults. (Located in the bottom left of the Shadow/Highlight Dialog when you check Show More Options. BTW, once you check Show More Options, leave it checked because that gives you access to the Tone Width and Radius sliders.) Now, the next time you open S/H the dialog will open showing more options and your image will not change until you apply some Amount to either the Highlights or Shadows Amount sliders.