The derived shadow can never resemble the body from which it proceeds unless the light is of the same form and size as the body causing the shadow.
 Leonardo da Vinci, The Notebooks of Leonardo Da Vinci (1478 – 1519). copy citation

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Author Leonardo da Vinci
Source The Notebooks of Leonardo Da Vinci
Topic shadow light
Date 1478 – 1519
Language English
Reference
Note Translated by Jean Paul Richter in 1888
Weblink http://www.gutenberg.org/cache/epub/5000/pg5000-images.html

Context

“That a shadow will have less defined outlines in proportion as the light which causes it is larger, and conversely, the outlines are clearer in proportion as it is smaller. [Footnote: The two diagrams to this chapter are on Plate IV, No. 1.] On the relation of derived and primary shadow (163-165) . 163. The derived shadow can never resemble the body from which it proceeds unless the light is of the same form and size as the body causing the shadow. The derived shadow cannot be of the same form as the primary shadow unless it is intercepted by a plane parallel to it. 164. HOW A CAST SHADOW CAN NEVER BE OF THE SAME SIZE AS THE BODY THAT CASTS IT.” source