Before reading this thread and the links I hadn’t thought about it but had assumed the moon illusion was due to refraction. So this was all new and fascinating stuff, for which many thanks. Having read and reread the links I think I grasp how and why the mind reacts as it does but the detailed explanations were clumsy and hard work to get through.

The points that wwh raised are answered there however; a camera does not make the same error as the eye/mind combination and different people see the illusion differently because their minds are fooled to differing degrees.

Worrying to hear that the same phenomenon has probably contributed to air and road accidents though.