171

On the shape of derived shadows.

OF PAINTING.

Of different shadows of equal strength that which is nearest the eye will seem the least strong.

Why is the shadow e a b in the first grade of strength, b c in the second; c d in the third? The reason is that as from e a b the sky is nowhere visible, it gets no light whatever from the sky, and so has no direct [primary] light. b c faces the portion of the sky f g and is illuminated by it. c d faces the sky at h k. c d, being exposed to a larger extent of sky than b c, it is reasonable that it should be more lighted. And thus, up to a certain distance, the wall a d will grow lighter for the reasons here given, until the darkness of the room overpowers the light from the window.

Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.

II * IV
Notebooks of Leonoardo da Vinci
III: Six books on Light and Shade.
. . .
151,
152
On the proportion of light and shade.
153,
154,
155,
156,
157
Definition of derived shadow.
158,
159
Different sorts of derived shadows.
160,
161,
162
On the relation of derived and primary shadow.
163,
164,
165
On the shape of derived shadows.
166,
167,
168,
169,
170,
171,
172,
173,
174
On the relative intensity of derived shadows.
175,
176,
177,
178,
179
Shadow as produced by two lights of different size.
180,
181
The effect of light at different distances.
182
Further complications in the derived shadows.
183,
184,
185,
186,
187
On the shape of the cast shadows.
188,
189,
190,
191
. . .