Originally Posted by
Mike Buckley
I will mention that one way to create the black edges of the glass vessel is to place a light directly behind the subject, shining toward it and the camera and to project that light through a white, translucent, diffusing material such as plexiglass, vellum or any photo diffuser. If you use that method, you will need to provide additional light on the colored balls but you'll need to avoid lighting the clear glass with direct light. One way to do that is to use only reflected light on the colored balls; if it also falls on the clear glass, it may actually add character to it. Another way is to use direct light on the colored balls while blocking the portions of the light that would otherwise fall on the clear glass.
The only other thing that I can add is that you don't have to feel limited by the number of your direct light sources. Many times the only way to achieve the desired image is to add white and/or black reflectors and sometimes even mirrors to the sides of the subject. I'm rather certain that that is true of your subject, which requires considerable skill and time to photograph just right.