The Darken tool is used to darken a specific area of an image. You could, for example, darken a light area of an otherwise well-exposed image to make it less emphasized.
In the Tool Options pane, customize the Darken tool:
Brush Size: Drag the Brush Size slider to adjust the size of the Darken tool brush. Hold down thekey to extend the range of the Brush Size slider beyond 100%. You can also manually enter a value from 0% to 200%.
Tip: You can use theand keys on your keyboard to change the size of the Darken tool brush.
Softness: Drag the Softness slider to adjust the softness of the edges of the Darken tool brush. With softer edges, the darkened areas will usually blend in better with the rest of the image.
Strength: Drag the Strength slider to adjust the intensity of the darkening effect.
Select a tonal range to darken:
Brush over the area of your image you’d like to darken.
Show Original: Click the Show Original button or press+ on your keyboard to see what the image looked like before you darkened anything in it.
Show Split Comparison:-click the Show Original button or press + on your keyboard.
Click Reset to discard all the current changes made with the Darken tool.