when I tested a camera I built earlier in the year, I tried an indoor shot (it was dark outside, and I wanted to try it out). It was a paper neg (guess a speed of about 5 or 10), but even in a brightly lit room, left for several hours, I got absolutly nothing (maybe a spot where it was pointed at the bare bulb!).

Obviously you're using faster film, but I'd guess you'll basically need to leave it overnight.

Ian