Another option would be to get Fred at the View Camera Store to do you film testing, then order a BTZS Power Dial from him. It's sort of a slide rule that helps you do exposure calculations. I've used one of these - make notes in a notebook of meter readings and use the Power Dial to determine exposure. You could also get the BTZS Lite CD from Fred, which is a much simpler explanation of BTZS than the book.