Yes this same type of lighting can be done with traditional sources. The thing is the projector allows for more detail, more control, on a smaller budget. Just imagine the the 40x60 or larger area the projector lights as one soft box face. Now the projector allows me to only let through say a 1 inch circle of light or an infinite amount of abstract shapes of darkness and light. This is something that would be much much harder to do with a traditional soft box. Generally when people try to light products in an extremely detailed manner like this many more lights and grids and snoots and grip are required. (this is a huge cost savings) Now yes my technique does require some playing with dynamic range; black inst always 100% black as contrast with projectors is better this issue is resolved, and it isn't always an issue. No matter how I shoot a backlit bottle it will be pathed out in PS. And generally I recognize achieving the final shot in one plate is impossible, but this means less plates and less time messing around with comps in PS later.
But to me the greatest advantage of this technique is I can sit at the camera look through the ground glass and see exactly what I am lighting. Even if I had assistants messing with grids, flags, masks, cinefoil etc and lighting budget was no issue I still wouldn't have 100% control on how I lit my object. (maybe a HUD display of the LV feed of the camera would be a close second) I generally open PS fullscreen and have a wacom in my lap, if I am looking an flipped image via sliding back ground glass I simply rotate my wacom. If I needed to use strobe I can still prelight with the projector and use the projected mask as a template.
