I am starting a photography studio and bought two softboxes and two umbrellas. In the softboxes, I have 5 florescent bulbs of 45 watts in each and one 45 watt bulb in each of the umbrellas. I have a Canon 40D and a 50mm 1:1.8 lens, and also a 70-200mm 2.8 lens. I would like to shoot 100 ISO and...