Level Adjustment
The Level Adjustment dialog box shows the distribution of brightness levels in your image. To adjust the histogram plot, drag the triangles located below the horizontal bar to the desired values. The left (black) triangle changes the shadow levels. The right (white) triangle changes the highlight levels. The middle (gray) triangle controls the midtone levels.
Level 
Adjustment
tab
Shadow control
Midtone (Gamma) | Highlight control |
| |
control |
|
By varying the Shadow points and Highlight points you can change the
relative shades and highlights of the image. The Shadow point represents6 the darkest value and the Highlight point is the brightest value.
