@Omenbringer, first thank you very much for taking the time to write that incredibly informative post. The material on the outside of the box is muslin. It is presently doubled over on itself. I'm thinking I'll need to remedy that. I am presently just using my cellphone camera, though my wife does have a much nicer camera. Perhaps I can convince her to help me out here.
So, here's my to-do list for my next attempt.
-Remove some of the diffuser
-limit the amount of white, by either framing the image better and removing 'headroom' (Would using a different background here help as well? Perhaps a dark blue or purple?)
-Move the cameras around a bit
Honestly, I probably didn't put quite as much effort into playing around with this last night as I should've before running here to whine and ask questions. Thanks again.
@Stark, that's a nifty little setup. Thanks for sharing it, but honestly photography isn't really my bag (if that wasn't clear enough already). I'm not sure $150 is an investment I'm looking to make.