This has bugged me for a while and after changing many settings haven't been able to find how to change it. Underneath my view point, be it following a AI aircraft or from one I'm flying (either in or out of the cockpit) there is a block of the scenery that is shaded a different colour from the rest of the ground. This always stays under the viewpoint as the subject moves around the scenery. It looks worse over sea and in low light as can be seen on one pic below. I'm running the Ground Environment add-on but don't think this is the problem. Any ideas or suggestions, even if just telling me it's a normal part of FS would be most welcome.
I've seen this effect in FS since way back before FS95. I think it has to do with the visibility range you set in the graphics options page, and I've also noticed that the textures you have loaded can also change how this effect is displayed.
I'm sure that better video cards and more RAM mitigate this effect, but other than that I've never been able to get rid of it myself.
