This is an unclipped high-dynamic-range image of a sky designed for image-based environment lighting. With a dynamic range of 21 EVs, it captures the complete brightness spectrum of the sun to provide realistic lighting and accurate shadows without clamping.
The environment map is supplied in the .hdr format at multiple resolutions to suit various performance needs. Included resolutions are 1K, 3K, 6K, and a maximum 10K (10000x5000 pixels) for crisp reflections and background rendering.