The right side of the slider can be moved to the left to reduce the span from that end. This effectively makes the entire image brighter as you can see in this example.<>/p>

Again, this example exaggerates the effect so that is it more obvious. You can see that the bright targets are almost completely washed out. As opposed to a cut-off threshold, this action results in increasing the overall image intensity. This can help when looking for dim targets at long ranges. In those situations, you should first attempt to increase the gain. The reason is that when you decrease the span from either end, you are reducing the number of shades of color available to be mapped and this will reduce the fine details of the image as the similar intensities will be rendered with the same colors. When the span is set to its full range, the color mapping presents the best color separation for slightly different intensities.