Mike,
I only just read this post, and must say a big thanks for your detailed information. I am new to portrait work, but realize I must start taking reference photos to suit, and actually just this morning I went to a church fair down the road, and bought an old "projector screen", stand included, and in great condition. I thought it may come in handy as a reflector screen for photography down the track. Or a backdrop, or something. Not bad for $5- (US $2.50). Anyway, I am getting organized so I can create some wonderful reference photos, and your info has been a help.
Thanks!