One of the most heartbreaking things is to discover that the shot you thought you had nailed was spoiled overexposed elements such as in this image:
However, with a bit of forward planning you can ensure you come home with something worthy of your talent.
The solution involves a little forward planning by taking two differently exposed shots as shown below.
IMAGE1: exposed for the subject
IMAGE2: exposed for the highlights
Now, let's get to work.
I use Paintshop Pro. Adobe users, you will have similar features, just slightly different.
STEP 1. Starting with IMAGE2, paste in a copy of IMAGE1 as a new layer
STEP 2. Right-click IMAGE1 and select 'New mask layer'.
What you'll end up with is something like this:
STEP 3: Click on the mask layer to select it.
Now, everywhere we paint black on the mask, effectivley cuts a hole in IMAGE1, allowing the darker IMAGE2 to show through.
Choose the paint brush and paint the top of that first big rock.
Looking at the layers on the right, you should see where we've painted onto the mask.
Now, continue to paint all those overexposed areas. You may need to change your brush size to get into smaller spaces. Also, try painting different shades of grey onto the mask to create semi-transparent sections.
After a bit of painting and a bit of fiddling, you should end up with something that looks pretty good.
STEP 4: Merge the layers down to a single layer.
Viola! This is your final image.
I hope that hasn't totally confused everyone. At any rate, there are plenty of other turorials out there if you want to learn more. This tutorial just scratches the surface of what you can do with layers and masks and the more you play with them, the more control you'll have over your images.