High dynamic radiance skydome panorama in *.exr and *.hdri format. Example scene in *.max file format included.
It is better to use as a texture on VrayLight in Dome mode. See example scene or tutorial video: http://youtu.be/6Ojf2VIL2tM?hd=1
You do not need to use additional lights (such as VraySun). This panorama were created in a special way to give correct lights and shadows. Just apply as bitmap in VrayLight texture slot, for example.
3d-preview (QuickTime needed): http://sky-hdri.net/images/icons/sky-HDRi-13_2011-06-29_15-20.mov
Visit sky-HDRi.net for more information.