Testing for Range Numbers

[Chuck_P45]

If using a reflection densitometer, am I to measure and graph the reflection density of the first differentiating black strip and the first differentiating white strip of the projected step wedge? OR, the reflection densities of Dmax and Dmin of the projected wedge? I'm thinking it should be the first differentiating strips next to Dmax and Dmin.

[Ed Pierce]

Go with the first visually noticeable almost black strip and the almost white strip. The Variable Contrast Printing Manual covers this in detail. It’s an interesting exercise, but I stopped using a densitometer and graphs because I use so many different papers and developers. If I tested them all I’d have no time or energy left to print! Now I just count the number of visible strips to get a “close enough” range number.

In my work, all I need a range number for is to determine the filtration needed to produce a “grade 2” with that paper and developer combination. This gives me my starting point.