The Darkroom

Photos © 2004, Frances E. Schultz, All Rights Reserved

How brown do you like your toast? The answer, of course, is "It depends." What kind of bread is it? How old is the bread? How thick? What are you going to put on it? How are you feeling at the time? You can't make hard and fast rules, even for yourself. It's even harder to make toast for someone else. How many domestic battles have centered around the settings on the toaster?

Photographic printing is very much like making toast: it's a question of personal preference and how you are feeling at
the time. Your toast (and prints) may well differ from mine, so we need to be able to make whatever adjustments suit
us personally.

Graffiti, Arles, South of France. Sometimes the only way to get a picture is to shoot in less than ideal conditions. These graffiti were never in full sun. The less important information is far better lit so I had to make some radical correction in the darkroom.

That's the wonderful thing about Variable Contrast (VC) paper. With just one box of paper you have up to seven contrast grades, and everything in between. If you want a different image tone, buy just one more box of paper: warmtone, cooltone, or neutral.

How Does VC Paper Work?
VC papers are coated with two emulsions, one high-contrast, the other low-contrast. One is sensitized to blue light and the other to green. More green light (or less magenta) means lower contrast; more blue light (or less yellow) means higher contrast. By mixing either green and blue or yellow and magenta light in different proportions, you can choose a stepless range of contrasts from Grade 00 (very soft) to Grade 5 (hard).

Graffiti: first work print. My initial work print was pre-flashed, then exposed "all in" at Grade 5. Next I burned the right-hand side at Grade 0. Remember, when you print the same area at two different contrast grades, the combined effect is the equivalent of a single grade in between the two. The processed work print showed me that I needed to dodge the left bottom corner and burn the right top corner, and also to adjust the exposure slightly, lightening the final print. You can see this if you compare it with the final print.

What Kind Of Enlarger Do I Need?
You can use any enlarger to print VC paper as long as you can place VC filters into the light path. These can go under the lens or into a filter drawer between the light source and the lens.

You can also buy special VC light sources. These are of two types: dial-in magenta and yellow filters, or cold light sources with blue and green light. VC light sources are most convenient because you can make very subtle changes, although anything less than a quarter of a grade is usually too subtle for anyone but a printer to notice.

There are different generations of VC filters. The current ones from Ilford are Multigrade IV. I find that my Multigrade IV filters used under the lens tend to give 1/4 to 1/2 grade more contrast than my Meopta Meograde VC head. Remember different manufacturers' filtration will give you different results. I can only report the results from the equipment which I have. Make your own tests.

Color enlargers can be used for printing VC papers as well. The principle is the same. Using the magenta and yellow filters, you dial in certain values for the grade you want. Check the paper manufacturers' recommendations, or see the table above. There have been quite a few charts published which give the values you should dial in. Not all of these charts agree. This one, courtesy of Ilford, is the one Roger Hicks and I published in our book Darkroom Basics (Collins and Brown, 2000). These values are for constant exposure times; you can use just yellow or just magenta filtration but you will need to change the exposure time with each setting if you do.

How Do I Choose A Contrast Grade?
The quickest and easiest way to establish the optimum contrast grade is via test strips. Make one set to determine exposure, and a second set to determine contrast at the chosen exposure. It is usually very easy to say, "This looks better than that," even if you aren't sure of the theory behind what you are doing.

I often use a Nova Step & Repeat Printer. I like it because it allows me to make six exposures of the same area on the print on only a half sheet of 8x10" paper. You can make something similar yourself out of card, with careful cutting, or you can simply use the old-fashioned approach of small torn strips of paper. Keep a soft pencil handy to write the contrast grade on the back of torn strips.

Wash them, dry them, and then decide which looks best. Drying is important: "dry down" can lose up to half a grade of contrast, depending on the paper.

As you gain experience you will find that contrast determination becomes second nature, especially if you use the same film, developed the same way and printed on the same paper, developed in the same developer. But even then you may need to burn part of a print at another contrast, as explained later. This time, make sets of test strips for different areas of the image.

Step & Repeat test strips for contrast. My Nova Step & Repeat test strip maker allows me to make six exposures. From my first set of tests strips (left) I already knew approximately what exposure I needed: about 8. I also knew that the two sides of the print could benefit from different contrast grades and different exposures. I made two test strips, one for the graffiti at 1-2-3-4-5 plus a second, longer exposure at Grade 5, and the other for the street at 0-1-2-3-4-5. When the two were dry I decided the graffiti needed a little less exposure at Grade 5, while the street scene would need about two stops more at Grade 2.