Using a volumetric spot light, it is possible to hide totally the elements that the light doesn't reach? I'm using a volumetric spot light, and in a animation, i'm moving the light so it shows some elements, and for now i got there three objects, but i do want to know if for example it is possible to totally hide (fade in totally black) the objects that aren't below the light, as you can see in the picture, those are still shown, as faded-gray objects.
I already changed the light strenght, but if i do that i lose another illumination detail that i already made.
Is there any way to fix this? if not ill just edit the video on an editing software using a mask.

Thanks in regard :)
You can change your spot with a 0 bounce (direct light only). The light won't bounce outside you volume anymore.



This will affect the lighting of your main object (no indirect light), so you can move the 2 others to another layer and add a "no bounce" Spotlight (duplicated or parented if animation is needed) and composite render layers. Your main object (with a spot with more than 0 max bounce) will have a nice direct and indirect lighting and the others won't be affected by bounces.

This setting was added in blender 2.73 official release (release notes)