Painting is one of the oldest activities of mankind. In trying to
depict a 3 dimensional world on a 2 dimensional surface, the ancients
began to try to understand human vision. The earliest written records
go back to Euclid in 300 B.C. trying to understand projection of 3
D objects on to 2D surfaces. However, the Greeks
were somewhat confused by the role of the eyes in vision.
Aristotle thought of the eyes as devices emitting rays, like modern
``laser range finders''. This view was
modified by the Moorish scientist Al Hazen in the 10th century who
suggested that the eye worked in the same way as a room (camera in
Latin) with a hole to let in light. Of course, this caused difficulties
in interpretation since the image in a pin hole camera is inverted
with left and right sides interchanged: how do we do see right side
up? This exercised many later minds including da Vinci, Descartes and
Kepler, but it took till the 19th century for
Helmholtz, Young, and Maxwell to establish that
even if the image were upside down, the brain could indeed interpret
the images the right way.
The next significant advance did
not come till the Renaissance in the 15th century Florence. In 1413
Brunelleschi created the first paintings which had a correct geometry of
perspective projection. These rules were codified by Alberti in 1435
in a text book used till the current day by painters. Other notables
who worked on establishing scientific principles
for the understanding of human vision were
Albrecht Dürer and Leonardo da Vinci. Da Vinci's studies of light
and shadow called chiaroscuro, umbra and penumbra are completely
superb. To this day these ideas are used by painters to give shape from shading.