The Da Vinci Notebooks at sacred-texts.com
A luminous body will appear less brilliant when surrounded by a bright background.
 I have found that the stars which are nearest to the horizon look larger than the others because light falls upon them from a larger proportion of the solar body than when they are above us; and having more light from the sun they give more light, and the bodies
which are most luminous appear the largest. As may be seen by the sun through a mist, and overhead; it appears larger where there is no mist and diminished through mist. No portion of the luminous body is ever visible from any spot within the pyramid of pure derived shadow.
122:108 : Between lines 1 and 2 there is in the original a large diagram which does not refer to this text.