Archived posting to the Leica Users Group, 1999/12/17
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]The moon seems larger at the horizon as we can compare it to familiar reference points: buildings, trees, cows... High in the sky, without reference points, it seems to shrink. This is a psychological/optical illusion that is easily verified by using your thumb at the end of your extend arm as a reference point. Try covering the moon with your thumb when the moon is low in the sky and when it is at its zenith. Alas, how life's illusions fall away. John Collier > Ted Grant, sage Nestor of us all, wrote: >> I have to question this size at the horizon and height above the horizon >> not making any difference in the size of the moon recorded and as seen by >> the eye. > Marc replied > This is certainly an "optical effect" but it is one as real to chemistry as > to the eye. That is, shooting a picture of the moon near the horizon makes > it seem larger than it really is, due to the effect of refraction through > the greater envelope of atmosphere, rather than the niggardly one when the > moon is overhead. (The difference is something along the lines of 100 > miles of air vertically versus 350 or 400 miles horizontally.)