Quote Originally Posted by Worker 11811 View Post
. . . You could cut the appropriate aperture in the side of the light bulb then slide it into a cardboard tube with the correct pinhole. . . .
I had thought to cut off the neck of the bulb and place the pinhole there for a full 360 degree coverage.

Thanks for the tip on submerging glass in water before cutting. This would also work on light bulbs by breaking the glass tip concealed in the base and filling with water before submerging.