DIY Negative Digitizer

So I don't have a scanner at my disposal that can handle 120 negatives but I want to get those size negatives into a digital environment. What am I to do? Today, I devised this contraption for shooting negatives with a digital camera. It is basically just a tunnel to keep out any unwanted light. I've attached an old flash extender as a camera mount to keep everything lined up and steady. (A strip of wood with a tripod adapter sized bolt through it would work pretty well.) The negative carrier is nothing more than a folded piece of mat board with a negative sized hole cut though it. The negative is placed inside the carrier and then slipped through a slot through the sides of the tunnel. Once everything is together, you can just point the whole thing at an even light source and shoot away. I pointed it a blank white screen on my computer. I think a white piece of paper with a light shining on it would work as well. The results probably aren't as good as you could get with a decent scanner, but after you get the file into photoshop, invert it and adjust the colors, it doesn't look too bad.