seems when Fly late afternoons with sun low and behind me, I get this small white ghosting of an image over the terrain below. When I pan say 90 degrees, it seems to go away! I'm using ND filters. Anyone else experience this? I would say ghost image is about 5 feet across on the ground. Quite annoying. I'm wondering if it could be a reflection of some kind or perhaps the ND filter is not up to par?