The manual "Exposure" value input is very important as it controls the upper light level displayed and provides a consistent light output required when comparing different fixtures, reflectors, or fixture locations. The "Max" value output above "Exposure" acts like a light meter and reports the maximum light level on the grid. This will change as fixture location changes.

Usually the exposure is set to a value that provides the best visual range for the screen rendering. The exposure can also be set to a maximum level dictated by the project. This mode allows realistic fixture comparison because the exposure is fixed, so differences caused by movement will be visually evident. In the example below the "Exposure" is set to the "Max" light level on the grid 59fc.

If the "Exposure" light level is set so that it is more than the "Max" grid value as shown below, the areas where the real light level is greater will be dimmer and appear under exposed.

If the "Exposure" light level is set so that it is less than the "Max" grid value as shown below, the areas where the real light level is greater will white out and appear over exposed.