All HDR images have been converted to cubemaps with a default size of 1024.

In each folder there is an info.txt files that provides several details about the capture as well as a multiplier to convert to an absolute cubemap.

Absolute Multiplier:

This multiplier can be applied to the white balanced cubemap to convert it from a relative to an absolute cubemap, i.e a cubemap that contains the real world luminance emitted by the environment.

Unity must be set to use the Linear pipeline for best results (whilst Gamma is supported, it will produce inaccurate results).