Environmental Brightness and Gamma

You can adjust the brightness and gamma of the light emitted by the environment image in a project.

Modifying the brightness of the environment image changes the exposure of the image. (The software changes brightness and contrast in real time. The source file of the environment image is not altered.)

Changing the exposure of the environment image alters the luminance (intensity) of the light that the image radiates into a project. (Everything except backplate images are affected by the light emitted from the HDR environment image.)

Modifying the gamma of an environment image changes contrast indirectly. Altering gamma also changes brightness, but in a different way than the Brightness parameter. Although gamma is not the same as contrast, you can use gamma to adjust contrast, while using brightness to adjust luminance. Used together, you can fine tune the combined brightness and contrast of the lighting in a project.

Because HDR images have so much data (32-bits per channel of RGB data), they have a wide contrast range. Therefore, small changes to the brightness and contrast of an HDR image usually produce high quality results.