I just got a Stouffer Transmission Projection Step Wedge in 4x5 size. It did not come with instructions, and I am not sure I know how to use it. I want to use i t to determine the characteristic curve of film/developer combinations and to fi nd Zone I and Zone VIII densities. I have a densitometer. The first step has a d ensity of .04. If I expose on Zone X with the step wedge over the film, can I in gnor the .04 denisty of step one and consider step one to be Zone X. Then would each progressive step be a half zone reduction: Step two is Zone 9.5. Step three is Zone 9. Is this correct?