http://www.sgi.com/grafica/light/index.html (Silicon Surf Promotional CD, 01/1995)
Properties of Light
The larger the light the softer the light.
The smaller the source the more contrasty the light.
The closer the light the softer the light.
Light Falls Off
A north light comes into a room and seems to disappear - It falls off.
Fall off is created by diffusion in front of a source which causes
the light to spin and tumble like a spinning curve ball.
It leaves the source, goes through the diffusion, spins and falls off.
Wrap Controls Fall Off
Wrap itself is beautiful.
The light embraces the side of the subject opposite the source.
It wraps around it, creating a gentle gradation of light to dark.
Wrap increases when the size of the light source increases.
Wrap is directly proportional to the size, angle and distance
of the source.
Wrap increases when you move the light closer to the subject.
Diffusion Enhances Wrap
Every time you add a layer of diffusion,
you increase the spinning effect of the light.
When light is spinning after being diffused, it literally clings
and follows the contours of the subject.
It wraps.