I have found 2.10 to be a really useful learning exercise. In the past I have tended to use it infrequently, and then primarily to correct exposure rather than as a creative process.
The original image I used was taken on one of our recent hot, sunny Spring days near the London Eye. It was grabbed in passing, so there was no time for any considerations of composition and lighting:
Accepting the compositional limitations, there are three things I decided could be done with this using the dodging and burning tools in Photoshop:
1. Bring out the faces of the three main characters. They’re a little too close in tone to the sky and don’t pop out enough for my liking.
2. The woman on the left, part-obscured face in the middle, white dress right-of-centre and the bright, white trainer sole at the bottom are distracting.
3. The background figures on the right are interesting in their own right, but perhaps aren’t quite distinct enough. The photographer in particular needs to be more prominent as he balances the woman to the left foreground and helps carry the left-to-right movement of the image through to the edge of the frame.
In the event I played around with Dodge and Burn for several hours and learned some valuable lessons in subtlety. Number one of those was to use a brush that is sized appropriately for the area being adjusted, and to keep feathering around 50%. As an example, each of the faces above was adjusted (after much trial and error!) with just one or two clicks with a large brush positioned centrally.
Exposure can be very easily overdone and I have settled on keeping it below 20% – and usually below 10%. Anything higher seems to end up looking unnatural.
Finally, brush the tools in the same direction as the lit textures in the image.