Graded Paper Comparison Test

[Bruce Pollock]

I'm planning to spend some time this winter in the darkroom doing some of those tests that we all think about doing, but never seem to get around to. You know, dry down tests, developer time and/or dilution comparisons, etc.

One of the things I want to do is prepare some prints that will show the difference between a Grade 2 and a Grade 3 (fibre based) paper to be used as reference in future printing sessions. As I thought about how to do this test, I realized I wasn't sure whether I'm testing for highlights or for shadows, so here's my dumb question:

Should I print for the high values and let the shadow values fall where they may? Or, should I print for the shadows and let the highlights fall? I'm assuming it's the former, and thus, I'm testing the difference in the two papers' ability to show shadow values. However, I would be interested in opinions or guidance on this.

I suppose it might be useful to test both approaches, but I think one is more logical than the other.

[Bruce Barlow]

Please print for the high values and let the shadows fall. Seems to me that paper grade ultimately defies testing - one tries an image on two grades and decides which one captures the feeling one likes. Not snap, not full blacks, but rather, does this better convey the feeling I want. So testing for contrast grades wouldn't be the best use of my time. Test for drydown, absolutely. Maybe test several different papers, and maybe test BIG differences in development time (I tested 2 and 6 minutes, the differences are surprisingly subtle when exposure is compensated for). But a day spent testing will give you huge knwoledge of your materials and I highly recommend it.

Good luck!

Bruce

[David A. Goldfarb]

To test for contrast grade, I'd also print for the highlights and let the shadows fall where they may, perhaps also testing development time like Bruce suggests.

I've found it very useful to buy a half-dozen 25-sheet packs of graded fiber paper and print the same neg on each of them. I keep a file for reference.

If you're interested in shadow detail, be sure to test Maco Expo RF graded. It looks great in Michael Smith's amidol formula for enlarging papers, responds well to toning, and will really show the difference between different developers. This is my favorite enlarging paper. For contact prints I use Azo. If I'm printing contacts and enlargements in the same session, I'll do the Azo prints first in Smith's Amidol formula for Azo, then add the requisite amount of KBr and benzotriazole to the tray and finish up with enlargements on Maco Expo RF. Michael and Paula's formulas are here:


http://www.michaelandpaula.com/mp/startframe.html (http://www.michaelandpaula.com/mp/startframe.html)

[Alan Barton]

While it may not make the most sense from a sensitometry viewpoint I would print different grade papers to the same Zone V/mid-gray (use a test wedge it makes comparisons easy). This allows you to see how fast darker tones change, how fast higher tones change and full tonal range. Once you have times for the same Zone V, print your reference print to understand how this works in the real world (which is all that matters). For completeness you should also know the minimum time to get a full black with your paper/developer combination .

[bob carnie]

If you are testing grade 2 and 3 , I agree with some of the posters above. settle for a nice upper midtone / highlight and see where the shawdows land
Assuming you are useing a normal negative that you feel represents the work to follow .. or what's the point?

You only know how you expose / develop therefore go with a negative that most represents you style

[Brian Ellis]

I'd suggest that you use a 21 step wedge rather than a normal negative for your paper grade test. That way you'll see the differences in equal half stop increments across the entire range of film densities as opposed to whatever range and densities just happen to be present in the negative you choose. It isn't easy to perfectly match the highlights (or the shadows) from one grade to another without a reflection densitomter since the two grades of paper will print highlights (or shadwos) somewhat differently if you leave the exposure the same but you can come closer using a step wedge I think.

[Ole Tjugen]

I've done a test like that, based on highlights (almost, but not quite white). I used a negative with very long scale, a 21 step wedge, and an Ilford EM10 lightmeter. It's well worth doing.