I just tried that with the compact fluorescents, and it WORKS!
The rings are there, and seem to be perfectly concentric, but how many should there be? Seems there's thousands of them.
-Tim.
-------------------- "We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"