For a very long time Steve Simmons and I have had a fundamental disagreement as to how the stain affects printing with graded silver papers. Steve holds that stained and non-stained negatives can not be developed to the same effective printing contrast. I disagree. Here is a fairly simple test that any interested party could to see which of us is right. It must be done with graded silver papers, not VC papers.
For this test you will need the following. A 21 step Stouffer (or Kodak) transmission step wedge and a few sheet of graded silver paper. Any grade will work, including any grade of AZO. You will also need at least one staining developer and one other developer, either staining or non-staining. If you have both PMK and Pyrocat-HD you could use them since this comparison is what sparked the present discussion. You will also need a light source that can be timed to 1/4 or 1/2 second. An enlarger with a digital timer with accuracy to 0.1 second will work fine. You will also need some print developer for your paper.
Please note. You must use graded silver papers for this test, not variable contrast papers. Variable contrast papers will indeed print differently in the highlights depending on the color of the stain.
Step 1 – Use whatever film you like. Take the transmission step wedge and contact print it to a sheet of film of whatever size is convenient for you to process. I do most of my testing with a Stouffer TP 45 step wedge and contact print onto 4X5 sheet film. This initial step will require some testing to get exposure in the ball park, but if you set your enlarger at a height needed to make about an 8X10 print from a 6X6 negative the exposure should be in the 0.5 second range at somewhere between f/5.6 and f/22. What you eventually want is to expose the test strip in such a way that when it is developed for about 12-14 minutes all but two or three of the steps will have some density. But at least two of the steps should just have B+F density for this test to work as designed.
Step 2 – Once you have determined a basic exposure time for your film, expose two or three sheets identically, i.e. same time and f/stop. Develop one in Staining Developer #1, whatever that is, another in either Staining Developer #2, and perhaps a third in a non-staining developer. This could be a PMK to Pyrocat-HD comparison, or a Pyrocat-HD to D76 comparison, or perhaps you may want to compare PMK, Pyrocat-HD and a non-staining developer such as D76 1:1.
Step 3 – Develop all three sheets of film for the same time, one in each of the developers. You don’t really know how much time each should be developed at this time, so let’s just arbitrarily say each should be developed at this point for 14 minutes at 72F.
Step 4 – When the step wedge negatives are processed and dried, you should now contact print them to graded silver paper. Use your enlarger light source, or if you print with AZO, whatever light source you use with this paper. It does not matter what kind of light source you use, but since the light source affects spectral sensitivity it should be the same for all three tests. You could use any grade you want, or AZO, but I would suggest a #2 paper so the numbers I am about to use will make sense. In making the prints you should expose each so that the last two steps, #20 and #21, print maximum density. Be very careful in exposing so the comparison prints looks exactly the same at Steps 20 and 21, and Step 19 should show just slightly less density. Careful reading of maximum density is critical for the later accuracy of the tests so make sure you get this right.
Step 5 – Evaluate the prints. Chances are that development was such that the step wedge prints do not all have the same effective printing contrast. For a graded #2 silver paper you should have a ES of about log 1.05, which is 7 steps, since each is log 0.15. As you know, this is an exposure scale of 3 1/2 stops, about right for graded #2 silver in contact printing. Look at the three test prints and see if one of them has a range of about 6-9 steps. Let’s assume that your print made from the PMK negatives has exactly 7 steps, the one from the Pyrocat-HD negative has 9 steps, and the one from the D76 1:1 negative has five steps. The PMK negative would be considered standard as it is correctly developed, the Pyrocat-HD negative is under-developed, and the D76 1:1 negative is under-developed.
Step 6 – Repeat the tests with Pyrocat-HD and D76 until the effective printing contrast is the same for all three negatives. In the above situation you will need to develop the Pyrocat-HD negative longer, and the D76 negative less. Visual analysis of the negatives, or even a densitometer reading, will not help you in this comparison since the stained negatives have more effective printing density than you see. However, eventually you will be able to match the prints so that all three negatives print with the same range of tones, from the shadows to the highlights. At that point, if you were to read the reflected densities of the three step prints and plot the curves, they will overlap.
Step 7 – Take your tests outside and make a few identical exposures of a scene. In the darkroom, develop each for the time required as determined by the above tests. If you have done a good job in testing the negatives , stained and non-steained, will print with exactly the same contrast
And now you know the truth, i.e. if you match the effective printing contrast of your negatives by adjusting time of development, there will be no difference in the way tonal values are reproduced, not in the shadows, not in the mid-tones, and not in the highlights. And that is true whether the comparison is made with two staining developers, or if it is made with one staining developer and another non-staining developer. Essentially, whether you use a staining developer or a non-staining developer it is possible to adjust time of development so that each will print with the paper ES.
This test asssumes that the developers used are non-compensating, and that is true in the case of PMK, Pyrocat-HD and D76 1:1 with graded silver papers. Both PMK and Pyrocat-HD provide a compensating effect with VC papers.
Try this test and report your finding.
Sandy King
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