Stretching can be accomplished manually though the Histogram Module or automatically through the preset stretches.
To use one of the preset stretches right click on the image and select the "Auto Stretch" to be applied to the image. From the menu bar, simply click the "black and white gradient button".
To manually stretch the image drag the black and white points in the histogram module. The lower histogram displays the stretch as it is applied to the image.
You can also select "Auto Stretch" which will apply a low stretch to any newly captured images.
Stretching images can be accomplished in a variety of ways at different precision: