Hi,
in new scene I found a problem and I dont think this happened in update 2. When I put higher directional value in light, this light turn to black in reflections and refractions.
Perhaps it is the nature of Directional Light.
https://forums.chaosgroup.com/forum/…622#post579622
https://www.facebook.com/vladimir.ko…0952442534808/
I think this is little bit weird and it turns black only in reflections and refractions, lights visible to camera directly is not affected and its white.
It’s not from Update 3. It’s a common behavior along all renderers. Unfortunately you’ll have to fake it for now.
The view direction changes between the direct PoV and that of the reflection, so i don’t see it as being weird at all: you won’t be able to see those “photons” only when a certain angle is passed, however that may happen.
Ok, you are right, that make sense. Its strange I never saw this previously before update 3 but if its there all the time, then ok 
Belittling the real physics, think of it as a Laser, where the photons’ directions are coherent (in the case of a continuous laser beam, one says they are “spatially coherent”) and where, without a medium to scatter it, you wouldn’t see it unless you were *exactly* in the line of fire.
The higher the directionality parameter in the V-Ray lights, the more “spatially coherent” the emission becomes, and so the behaviour becomes more similar to a laser beam.
The “fix” is going to be a cheat, in fact, albeit a useful one.
Alternatively, you could add a very thick fog to your scene! (kidding! ^^).