Why doesn't turning off a light make my scene darker

The first time I tried out Lighting Channels I was confused that lowering the intensity of a light
didn't make the scene darker. The same effect is true when you add or remove a light from your SketchUp scene.

The cause of this is Automatic Luminance or Photometrics
Automatic Luminance or Photometrics automatically adjusts the overall intensity of your rendering, much like the automatic exposure on a camera.

If you want to adjust Lighting Channels or other items without having Photometrics apply, you can lock the Average Luminance on the Lighting Channels Wizard.

In the latest version of IRender nXt we have changed the default setting, so that the Luminance is locked when you make adjustments to lighting channels.




If you decide to unlock it - so that the exposure is recalculated as you modify lights - uncheck this box. Whatever setting you choose will be remembered the next time you use lighting channels.


For more information, see: Lighting Channels