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coops
8-Jul-2009, 09:26
I have read that many photographers use a step wedge and densitometer to do paper testing. I thought the test print in 2-3 second increments was the way to determine the best exposure for any given negative? I am a little confused and a quick search did not turn up details regarding paper testing that made sense to me.
Any advice appreciated. Thanks

Bruce Barlow
8-Jul-2009, 10:31
When I did my paper tests, I lost a good friend when I didn't take his advice and use a step wedge. That apparently enraged him enough to walk out of a friendship.

However, I pointed out to him that I didn't make many pictures of step wedges, and so had little use for prints of step wedges. I used a real photograph instead. I'll bet I learned much more doing that. I ended up making over 400 prints of that negative. Amazingly, I still like it.

It's akin to a test report I read soon after in Photo Techniques, where the three authors refused to print pictures with the paper being tested (Kodak Polycontrast IV RC - a good paper), and instead ran all the step-wedge and densitometer tests. They concluded that the paper would "probably" make nice prints. I have never gone near that magazine since.

Download my paper and print developer articles from my web site for free. Then, make real prints with the papers you want to learn about. You'll learn a lot about the papers and about a lot of other things. Have fun!

coops
8-Jul-2009, 11:16
Download my paper and print developer articles from my web site for free. Then, make real prints with the papers you want to learn about. Have fun!


Thanks Bruce. I will do that.

jeroldharter
8-Jul-2009, 11:44
The best way to learn about testing is the read the BTZS information. Even if you do not use those methods, understanding them will help you. For VC paper especially, step wedge tests with densitometer values and corresponding graphs are a great way to see how your paper will respond at various contrast settings. It is also a means to find a paper that suits your film characteristics and your preferences.

Certainly there is much to be learned by empirical testing. However, the point of using a step wedge is to save yourself that labor and time of printing a negative many times to develop a feel for your process.

CG
8-Jul-2009, 13:34
There are different reasons to use a test strip, and a step wedge and Kodak's Projection Print Scale. Each has it's value and it's weaknesses. When I refer to test wedges, I mean stepped density scales like Stouffer's 17 or 21 step density scales.

For determining the "scale" of a paper:
A step wedge is a useful tool. and for an objective reference to show what, say, toning does to various densities, very good also. It provides a very compact reference to keep on file of the results of say a bunch of different papers and developers etc. It does not replace actual images from negatives.

For finding exposure to make a print:
A test strip is good to get a starting exposure for a particular print and to get an idea of burning, dodging etc.

The Kodak Projection Print Scale is kind of like a "pie chart" step wedge is similar in intent to doing test strips, and oddly hard to use. I suspect most folks find a simple test strip more useful.