Hmm...

It just occured to me what the cause of this little puzzle is. Naturally,
the solution has come to me only *after* posting my question. :-[

The sphere to the right is not part of the light_group, so where it intrudes
into the left sphere, the light doesn't interact with that part of it...the
"left side" of the lens shape. Very logical. The part of the left sphere
that's on the "right side" of the lens shape IS part of the light_group,
and its media is being lit as it should be.  Again, very logical. The fact
that my camera is looking straight-on at the spheres is the cause of the
"artifact"  It's just a viewing-angle problem!

Ken

Post a reply to this message