2008

Desaturate Low Levels simulates the eye's response to dim lighting. In dim

lighting, the eye does not perceive colors and sees tones of gray instead.

The effect of this setting is not apparent except at very low light levels, below

5.62 footcandles (lumens per square foot). When the illuminance is less than

0.00562 footcandles, the scene is completely gray.

NOTE 1 footcandle (fc) equals 10.76 lux (lumens per square meter).

Logarithmic Exposure Control

Rendering menu > Environment > Environment and Effects dialog >

Environment panel > Exposure Control rollout > Choose Logarithmic Exposure

Control from the list. > Logarithmic Exposure Control rollout

Logarithmic Exposure Control uses brightness, contrast, and whether the

scene is outdoors in daylight to map physical values to RGB values. You can

use it with either the

default scanline renderer on page 5949 and the mental

ray renderer

on page 6039 . Logarithmic Exposure Control is best for scenes with

a very high dynamic range.

Left: The intensity of an IES Sun light completely overexposes a scene.

Right: Logarithmic exposure control corrects the overexposure.

Logarithmic Exposure Control is the best type of exposure control for

animations because it doesn’t use histograms.

TIP If you're rendering to texture on page 6169 , use the Logarithmic exposure

control, not the Automatic or Linear control.