Adjusting images : Brightening images
 
Brightening images
Lighting problems are common in photography. Photos taken in bright light often lack detail in the shadow areas. If your photo’s background is too dark, or if the difference between the photo’s light and dark areas is too great, you can lighten the darker, underexposed areas. You can adjust saturation, which is the purity or vividness of a color.
For more information about other brightening features, including Fill Light/Clarity, see Adjusting brightness, contrast, and clarity.
To brighten a photo
Edit tab 
1 Choose Adjust Fill Flash.
2 Type or set a value from 0 to 100 in the Strength control to determine how much to lighten the darker areas.
3 Type or set a value in the Saturation control to determine the overall saturation of the photo’s colors.
Values less than 0 reduce saturation; values greater than 0 increase saturation.
4 Click OK.
If a photo has areas that are too light as well as areas that are too dark, choose Adjust Fill Flash, and then choose Adjust Backlighting.