Paul C. Buff, Inc. Technical Forum

that sounds about right. I didn't have my light meter with me on Tuesday, so I was just using trial and error. My studio space is about 18-20 X 12 foot. I have 4 backdrops on 4 walls with a softbox in the middle and an umbrella off to the side. I just rotate the softbox, so I'm thinking I may need to downgrade to the B400.