This feature is automatically enabled for all terrain schemes, except YouSee.
Let's take this example of terrain map. The central valley has a terrain altitude of about 700m, and expecially on the mountain pass over Tonale Avio, which is at 2000m!, it is painted brown.
Now let's zoom in a bit, to get a local view or where we are flying, like in a real situation.
As you can see, the terrain has now a better contrast. Let's zoom more.
Here we can better see the autocontrast action. Terrain is painted green, not brown.
LK8000 is rescaling the terrain using as the ground base the minimal altitude painted on the current map.
Under many situations, when you are inside a valley, this feature will make a big difference while looking at the terrain map on you screen! The effect of autocontrast (or better call it autorescaling) is different depending on the color scheme in use.
Now let's take the terrain in germany near Porta Westfalica. We use High Contrast to emphasize low hills.
And now zoom in to see the autocontrast in action..