How to use the Adjustment Brush

The Adjustment Brush can be found on the Camera Raw editor in the left-hand sidebar, fourth down from the top. Look for the paint brush symbol. The Adjustment Brush remembers whichever settings you last used with it. Click the three dots and select Reset Settings to bring all the settings back to their defaults.

You can adjust the size of the brush using the bracket keys [ and ] on your keyboard or by using the Size slider. To apply the adjustment, either start painting over the area you want to change then tweak the sliders (for example, push the Exposure slider up and see what happens), or adjust your settings first, then paint those settings onto the image. Starting to paint creates a pin, which you can use to manage this set of brushstrokes.

To get a new brush for another part of the image, click on the plus symbol at the top of the settings. If you go wrong, you can either delete the entire pin by right-clicking on the pin and selecting Delete from the resulting pop-up menu, or select the pin and press the Delete key.

You also have options to show a mask by clicking the Mask Options box, while clicking on Overlay toggles the visibility of the pins. You can click and hold the eye icon to see how the image looked before you started your adjustments, for comparison, while the arrow symbol resets the image back to the starting point.