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.

[Chuck_P45]

The Variable Contrast Printing Manual covers this in detail.

I see where it covers it nicely when evaluating for relative ISO RNs visually, but I don't see where it mentions the process of actually using a reflection densitometer to arrive at the RN.

Thank you for the input, I was beginning to wonder if anyone participated here anymore.......sort of almost gave up on it.

[sanchell]

That's my bad, Chuck. I am scheduled to receive notice when a post is made. About a year ago I changed web hosts and in the migration the link appears to have broken but I just thought there were no new posts. Just to be sure, I checked the forum every day for several months and when there were no new posts I drifted away from checking and then after a while forgot to do it. I finally became curious and checked again a few days ago and found three posts. I have my IT guy working on fixing it.

My apologies.