Better Pictures In Any Light - 3/24/08
Rescue lost shadow detail with the Shadow/Highlight tool
I don't know if exposure accuracy has gotten better or worse in the post-light-meter, LCD-checking era, but I do know this: If I'm off by a little bit, I've got a lot of options to fix my shots in the computer.
One of the most common problems I run into in terms of errant exposures is a loss of detail in the darkest shadows of an image. Most times it may not present a problem; after all, a dark shadow is supposed to be dark. But sometimes a few crucial details disappear in those dense spots, and that's especially bad when those details are important to the subject. A common example of this is a loss of separation between a dark background a subject's dark hair in a portrait. With just a hint of detail, separation-and the illusion of depth-is better created.In other cases, an overall dark exposure may be just right to set the mood, but a little too dark to make the image pop. There are many ways to rescue hidden image details, but my favorite for pulling information out of deep shadows is Photoshop's Shadow/Highlight adjustment tool. Found in the Image > Adjustments menu, Shadow/Highlight does just what the name suggests-it allows you to work on the shadows and highlights in an image, pulling each of them back from the brink of oblivion.
The first step of my process is to duplicate the photo onto a new layer so I can always easily go back to the original. Next, in Photoshop's Image > Adjustments menu, choose Shadow/Highlight to bring up a dialog box with two sliders and values. The easy method is to simply drag the Shadows slider to increase or decrease the amount of detail you'd like until it looks just right. For a more advanced method, click the Show More Options box in the bottom corner, and you'll have plenty of control for adjusting both shadows and highlights in the image.
From here, adjust the tonal width and radius to further increase and decrease the brightness of the adjustment. Increased tonal width is a lot like boosted general brightness, whereas an increase in the radius value looks a lot like a contrast kick. Adjust all the sliders until you're happy with the results, and consider going a little beyond what is most pleasing to your eye, because you can (and should) adjust the layer opacity to bring down any changes that are too dramatic.
Even better, continue to fine tune the effect by using the Eraser tool or layer masking to selectively eliminate (and therefore darken) places on the image where you don't want the overall increase in shadow detail. This is a simple yet crucial step because it turns a wholesale change into a more refined adjustment-almost like supercharged selective dodging and burning in the darkroom.
Your photo is now near perfect, with better shadow detail exactly where you want it-much better than the image you began with. But if you'd just like to keep going with the modification, don't hesitate to further tweak the layer opacity, contrast or even remove some of the additional noise that the Shadow/Highlight tool is bound to uncover. In any case, those once-lost details are now revealed with a simple digital tool.