Thanks I made a spreadsheet to calculate reciprocity and bellows ext factor. It came out to 20 secs instead of 1. 15" bellows draw and 1 second exp. 8 1/2" lens. Sound even remotely correct?
I know film is expensive, but an experiment you might want to try while you are starting out is to bracket two stops longer, then compare the negatives. I have been starting out for about eight years now and I really like the choices that produces.
"If you want to be famous, you must do something more badly than anybody in the entire world." Miroslav Tichư