Bill S. wrote: > While I settled on APX a little arbitrarily, I want to decide on the developer > more by trial. So many combinations, so little time.....
Sorry to say, but it's pretty much a fool's errand. The three factors that have an effect on image gradation are the film, the film developer, and the paper, called FDP. (No, paper developers aren't significant.) Different developers have an effect on a film's curve shape, which must then be matched to the curve shape of the paper. What most photographers don't realize is that when they choose one or even two of these three factors arbitrarily, they aren't really learning anything real about the properties of the third factor, no matter how careful their experiments are. Let me give you an example. Let's say there are two black-and-white photographer / darkroom workers. They've both chosen Film P. They're both looking for the "right" developer for Film P. But Photographer 1 uses a paper that has very high highlight contrast, and Photographer 2 has been told that a paper with very low highlight contrast is nice. So Photographer 1 will search around to find a developer that gives Film P low highlight contrast, which matches his paper. Photographer 2 will search until he finds a developer that gives Film P high highlight contrast, so it matches well with _his_ paper. Then Photographers 1 and 2 meet at an opening, and each one says to the other, "man, I really like your prints. What paper do you use?" Photographer 1 subsequently goes back to his darkroom and tries Photographer 2's paper, and finds that the highlights are hopelessly muddy. Photographer 2 goes back to his darkroom and tries Photographer 1's paper, and finds that the highlights are completely blown out and impossible to control. Both photographers go away muttering "that stuff really sucks." They also each think that developers with pretty much opposite properties are "the best" developers for Film P. Of course they haven't really learned anything about the materials. To make matters worse, lots of photographers use FDP combinations that aren't terribly well suited to the visual affects they want to achieve, so to some extent they "fight" the natural tendencies of the FDP combination they've chosen, using various tricks and techniques to "force" the materials to look the way they want them to. Most times when you hear tales of Herculean efforts in the darkroom, about how some printer has such high standards that it takes him a day and a half to make a great print, it's usually just a sign that he hasn't chosen materials that match each other or that lend themselves to yielding the look he's trying to achieve. Phil Davis devised about the world's most elegant way of reducing all these shifting variables to the realm of objective science. He designed a computer program called the Plotter/Matcher that takes sensitometric data for films in various developers and plots curve families for them, and then matches these curve families to the curve plots of papers and predicts gradation on a bar chart (vis a vis a theoretically "perfect" or rather "perfectly average" scale of grays). It's not quite so simple as that, but that's the gist of it. With a full set of data, which unfortunately takes a very long time to compile, you can compress literally _years_ of darkroom experimentation into mere days of work on the computer. You can find out why certain combinations tend to fight your best efforts, and what the properties of materials actually are. It doesn't take long to arrive at an FDP combination that effortlessly renders your preferred gradation. Printing becomes relatively simpler and much faster. Each print needs far less manipulation in the printing stage and most prints seem to "print themselves. The properties of FDP combinations that most photographers look at--graininess and perceived "sharpness," which is essentially a quasi-mystical jumbo of vague unmeasurable terms like "acutance" and "edge sharpness" and various hokum words alleging to describe grain--fall FAR below gradation in importance, and they're ill understood at best (for instance, the old wives' tale that Rodinal has "high acutance" is overwrought--in fact, D-76 1+1 has acutance just as high. Rodinal's main characteristic is actually that it depresses the middle values of most films somewhat--that is, a Zone V tone will be moved to a Zone 4 1/2 value, etc. If you don't like this "look," it'll give you fits in the darkroom trying to correct for it, and you'll probably end up making compromises somewhere else in the tonal scale to compensate). And there are so many influences on grain it's difficult to list them all, Given the right equipment, I can make prints that seem to have "fine grain" and "lots of grain" from the _same negative_. Bottom line is, get the gradation right, and from there you can make pretty much everything else fall into place. --Mike - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
