I had an occasion where I needed to light an object from underneath (the glass of beer in the pic above). I wrestled with it for some time, and then came up with what turned out to be a pretty easy solution.
Using a flat fluorescent light fixture I picked up at Home Depot, and a piece of black craft foam, and my large DIY light tent with glass riser, I was able to get the photo above. I cut a hole in the black craft foam that was roughly the same size as the base of the glass. I then put my black backdrop into the light tent, set the fluorescent light on my workbench inside the light tent, and then placed the craft foam on top of that so no light escaped except through the hole I had created. From there I inserted my glass sheet to have a riser (which was conveniently about an inch higher than the surface of the fluorescent light), filled the drinking glass with beer, and turned on the light. This photo did not require any additional lighting other than the fluorescent underneath the product. And by using the pane of glass as a riser, a nice reflection appeared as well.
That’s all there is to it, hope it works for you if you need some illumination from underneath on an object.
Shooting Glass Today in Lakewood, Colorado
Today I am doing more product photos in my Lakewood home studio for the Community Carbon Project. Doing some experimenting, and since I don’t have a laptop, trying to connect a bunch of USB cables together to do some tethered shooting. We’ll see how that works out. In the meantime, enjoy the above photo, which I think has come a long way from my first attempt.