Originally posted by womble I have a book (?"Beyond the zone system" I think) that has a blueprint for making one using a Spotmeter. .
I have that book too. If you make one, get a calibrated step table from the manufacture in lieu of a uncalibrated one and then taking it to some place to have the densities read. I did that at first to save money but ended up costing me more to eventually get the calibrated one.
My reasoning was the one-degree hack is less accurate than a good densitometer and the readings from that lab I took it to introduced more errors ( like a copy from a copy). Mine first one was an uncalibrated Kodak step table and Kodak guaranteed each step was a fixed density value from the previous/next step but does not guarantee the steps will be the exact density value (eg 0.15, 0.30, 0.45, etc) they should be ( eg 0.16, 0.31, etc). The readings from the lab were not the same delta difference from one step to the next.