If you're using ordinary lihgts, how do you make a gobo? I'm using dome (scoop) lihgts from lowes. regular or flood bulbs. I tried making a venitian blind gobo, but it doesn't seem to work. I don't know if it's cause of the light, or what. I can somewhat make it work, but the trick is, the light/gobo have to be pointing at a strange angle. I don't understand what I'm doing wrong