We recently (2009) purchased the last remaining inventory of LF Deardorff & Sons, Inc. Included amid the thousands of parts we bought were a whole case of bellows exposure calculators called "EZ-View." They're brand new in the plastic case. If any of you are looking for them, look on eBay at our store.
Barry C. Cochran
LF Deardorff & Sons, Inc.
eBay seller: Attrevida
I haven't read all the threads but since I would rather not do the math especially when out. I took a small retractable tape measure and did the math for each of my three lenses and marked the exposure factors with a different color for each lens with a permanent marker. I just measure from the lens to the film plane and see what the adjustment is. I keep the tape connected to the strap of my lightmeter. The tape measure is about 2"x2" very cheap in your favorite hardware store.