In a darkroom, you solarize a print by intentionally exposing it to the light while it's developing. In this case, lighter areas, which have not yet developed, turn dark. You can reproduce this effect by reversing the greys in a selected range.

1. Select the cropping tool from the tool bar, and then select the picture whose image you want to fine-tune.

2. Choose Image Control from the Edit menu.

3. Position the pointer in the greymap box in the upper-left part of the box, and drag diagonally to the lower-right.

4. Click Apply to see the results in the picture.

5. Click OK when you're done.