I’m sorry, my mistake!
I am talking about the invisible check box in the VRaySun not VRaySky (now it’s correct in the previous post).
If you put the same map first in the environment slot and hit render then you got the sun as a white disk; this doesn’t happen if you use that map as texture map in a dome vrlight.
About the matedit issue I use LWF too (+ reinhard CM) but I’m still having white slot; it seems someway related with the auto update issue that someone already found.
Other missing infos are that if I use the Physical Camera I have to leave the VRaySun to its default value, so I can’t use the “0.01” trick.
yeah the “proper” workflow for sun/sky/cam is to leave the sun and sky at default 1.0 multiplyers and then use the physical camera to control the light. That way the osi and f-stop values of the camera match close with a real world camera.
But your right the mat editor vraysky preview is always blown out.