The Lighten tool tones an image by enhancing the brightness of colors. Each stroke applied increases the lightening effect.
The basic tool settings are shown in the Tool Options panel above the Image Window or by right-clicking on the image. To display the full list of parameters, press the tool icon in the Tool Options panel or use the F5 key. To specify the parameter settings, enter a numerical value in the parameter’s field or use the slider.
Element - in the drop-down list, select the type of the basic element of the brush: Ellipse or Select Shape.
Size (1-5000). Diameter of the Lighten Tool.
Hardness (0-100). The degree of softness of the tool's edge. The higher the value, the sharper the tool's edge are. At 100% there is a sharp transition between the affected area and the unaffected area; at lower values the transition between these areas is smoother.
Strength (1-100). Amount of Lighten applied to an image. When Strength = 100% the maximum amount of lightening is applied to an image.
Fill (1-100). The intensity of lighten effect with a single brush stroke. If you hold the mouse button while drawing, the strokes are overlapped and the lighten effect increases.
The drop-down menu Range contains three ways to process pixels:
Shadows. Darker areas are processed more than lighter areas.
Midtones. The brush affects both light and dark areas equally.
Highlights. Lighter areas of the image are processed more than darker areas.
In addition to the above-mentioned parameters, you can adjust the advanced settings that affect the shape and position of the brush marks.
Press the Default button to set all settings to their default values.
To lighten an area in a straight line, first select the starting point by clicking the left mouse button, then, while keeping Shift pressed, bring the cursor to the desired end point and release Shift. If Shift is not released, additional lines will be drawn to each point where the mouse is clicked.