Trampas Peak Eclipse

This is best understood by comparing angular size of the moon compared to the angular field of view (AFOV) of the lens used.  The moon is approximately 0.5 degrees in size. Long focal length lenses have a small AFOV.  For example, my 600 mm lens has an AFOV of (3.4 deg, 2.3 deg) in the (horizontal, vertical) direction.  A moon photographed with a long focal lens will look big since the moon’s angular size (0.5 degrees) is a large fraction of the AFOV of the scene captured by the lens.

Conversely, using a wide angle lens the moon appears as a small dot in the night sky since the angular field of view of the scene captured is wide.  A 24 mm focal length lens has an AFOV of (73.7 deg, 53.1 deg) in the (horizontal, vertical) dimensions.  The 0.5 degree moon is tiny compared to the horizontal width of 73.7 degrees.

The angular size of the moon is 0.5 degrees, whether it is on the horizon or high in the sky (outside of a tiny correction for atmospheric refraction).  The moon is also 0.5 degrees in size when looking through a wide angle lens, or a telephoto lens.  It looks very big when looking at it through a telephoto lens since the angular field of view (AFOV) of the telephoto lens is small.

The cone of visual attention of the human eye has an angular field of view of about 55 degrees (equivalent of a 43 mm focal length lens).  Our eyes can notice movement and broad shapes over a total angular field fo view of 160 degrees though.