Fine-Tune Image by Modifying Adjustment Layers
Although there are a dozen ways to lighten or darken small portions of an image, the use of adjustment layers and masks has made the technique easy and non-destructive.
In our photo of the young African "Jack Fruit" girl, we see a need to lighten only portions of the image in order to balance the overall look for clarity. The surrounding foliage and water is just about the correct exposure, however the platter of jack fruit is seriously shadowing the little girl's stern expression. We'll need to lighten her just a bit, without disturbing the rest of the image.
Adjust for target settings: Initiate a new Adjustment Layer for Levels. (Layers > New Adjustment Layer > Levels)
Move the right slider toward center, and the center slider toward the left. The beauty of the Adjustment Layer is it can be infinitely tuned until just the right look is achieved.
Notice however that during the process, we've made the scene too light -- -- taking away the richness of foliage along the banks of the Nile. That will be easy to fix by modifying the adjustment layer's mask.
Modify the Layer Mask: As with most adjustment layers, a mask is applied to the right of the layer thumbnail. Here's where all the action will take place
Click on the Mask
Fill it with black
Paint White to Reveal: Now, use an appropriate brush size and opacity and begin painting white into the mask to reveal just those areas that need lightening.
We have pre-tuned the Levels in this adjustment layer to provide the desired lightness of the girl. The BLACK completely hides those adjustments. As we paint white into the mask, those adjustments once again come into play.
Notice, I'm painting along the platter, down the arm, and within the face. (See the white shapes in the black layer mask at the far right above.) I'll also just lightly touch areas of the little boy's features to lighten them as well.
Before finishing, I want to add a slight bit of "richness" to the overall scene with a Contrast/Brightness Adjustment Layer. Now the image is ready for flatening and further use.
The pros might take a somewhat different approach, using curves or further modifications. You should experiment with the above techniques to see if that's the cure -- or if you want to investigate other options.
For that, you need to buy
Adobe Photoshop Restoration & Retouching by Katrin Eismann. She is the world's leading expert, and will easily show you how to get spectacular results on such a retouching job.
Good luck, and thanks for reading.