The key combination Ctrl-D will change the active tool to Dodge or Burn tool.

Ctrl toggles between dodge or burn types. The type will remain switched until Ctrl is released.

Shift places the Dodge or Burn tool into straight line mode. Holding Shift while clicking Button1 will Dodge or Burn in a straight line. Consecutive clicks will continue Dodge or Burn in straight lines that originate from the end of the last line.

The available tool options for the Dodge or Burn Tool can be accessed by double clicking the Dodge or Burn Tool icon.

The Opacity slider sets the transparency level for the operation. A higher opacity setting results in a more opaque render and a lower setting results in a more transparent one.

Indicates the active brush. Clicking on the brush icon opens the brush selection dialog.

If this option is toggled on, the tool behaves like the Pencil tool, in the sense that there is no anti-aliasing, and pixels are affected in an all-or-nothing way, even if it is being used with a soft brush.

The Pressure Sensitivity section sets whether hardness, rate, or size will be affected by pressure for input devices that support this option.

This option causes a transition to the background over a distance set by the Length field.

The dodge effect lightens colors.

The burn effect darkens colors.

There are three modes:

Exposure defines how much the tool effect will be strong, as a more or less exposed photograph. Default slider is 50 but can vary from 0 to 100.