Purpose
To switch between relative intensity and absolute intensity mode.
Usage
Click the rel intensity box to change from rel intensity to abs intensity.
Comments
Use rel intensity when you want the intensity to be relative to the light meter's position. As you position the light source, inputting the value 1 will result in the preferred light intensity for objects at the light meter's position. A percentage of the preferred intensity may be used by inputting a higher or lower value than 1.
Use abs intensity when you do not want the intensity to be relative to the light meters position, for example when using multiple light sources with each light source requiring the same intensity. By inputting the same absolute intensity for each light source, the intensity will be consistent for all light sources.
See also
light meter