About light beams ...

Hi,Having experimented with the Light() command for iluminating posts I came across a problem that one would get on non flat areas.In fact the light beam is made of a light cone (only seen when visibility is less than 5nm) and a projected light on the ground. The problem is with the ground projected light. It goes high and down depending on the altitude above ground of the viewer. If there is a valley near the airport, the ground projected light descends (becoming larger and disappearing after a few meters) when the viewer goes to the valley. If there is a mountain, the ground projected light rises in the air (becoming smaller until it becomes a point when it reaches the focus) when the viewer goes to the mountain.This is what it should be for a landing light with its focus connected to an aircraft, eg, to the viewer. In this case the distance "focus to ground" varies according the terrain underneath the viewer. But for iluminating posts, the focus is on the top of a mast and the distance "focus to ground" should not vary!Anyone got this problem? Any workaround?Kind Regards, Luis