Adjusting images : Darkening images
 
Darkening images
Sometimes photos have too much lighting from the background, which essentially washes out the entire image. A similar problem involves photos with too much flash on the subject. You can darken the bright, overexposed areas of a photo.
To darken a photo
Edit tab 
1 Choose Adjust Backlighting.
2 Type or set a value from 0 to 100 in the Strength control to determine how much to darken the lighter 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.