Just my thoughts on the illusion in case it's helpful. I saw this illusion tonight when I suddenly saw the moon behind the top of a distant tree. I think the s

Just my thoughts on the illusion in case it's helpful. I saw this illusion tonight when I suddenly saw the moon behind the top of a distant tree. I think the suddenness adds to the illusion, and the explanation of the brain's image processing reasoning about the size because it is compared to something distant feels right. It does not feel just a small amount bigger - at least double the usual size. Even as I looked at it, the illusion weakened. It was obscured by trees and building as I walked towards it, and again I saw it rise again over a building a little way off. The illusion repeated, though not as strong. Much later I saw the moon in the sky, and it looked normal size. I do not have the illusion anywhere near as strongly when I look at that skyline photo, although I can sort of see what they are trying to describe. I think many photos of the moon zoom in, greatly increasing the apparent size, and I don't think this is the same as the illusion, although in a way, comparing the moon to a building which is known to be large may contribute to the illusion we perceive when seeing it in real life (not in a photo).