i project onto cheap flat black material (mostly i use a big piece of black velvet that came out of my photography light box).
i use a nikon d7000 with exposure and focus locked on manual and i shoot at iso 100, f20, 1/30th of a second exposure time and 30 fps.
your milage may vary, but that should be a reasonable start. if the video is too dim, change the f-stop to a smaller value, or increase the iso.
suppose you're thinkin' about a plate o' shrimp. Suddenly someone'll say, like, plate, or shrimp, or plate o' shrimp out of the blue, no explanation. No point in lookin' for one, either. It's all part of a cosmic unconciousness.