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In Defense of Testing
by Phil Davis

Arguments about art photography and religion have at least two things in common: they’re both likely to be based on supposition, wishful thinking, prejudice, and blind belief — rather than on fact — and they tend to generate more heat than light.

This is understandable because there really isn’t much factual basis for assertions about either art or religion. Discussing either can be entertaining, and occasionally inspiring, but sooner or later we have to recognize that there are no definitive answers, and one person’s opinion — no matter how unpopular it may be with the majority — is just as valid an any other’s. We sometimes find this difficult to accept, though, and if a religious argument becomes irrational and turns ad hominem it can escalate into something approaching a holy war — as witness the Crusades. We can be thankful that art arguments haven’t reached these ridiculous extremes, at least not yet.

There’s no reason why they should, either. Although we’re not likely to learn anything specific from them, debates about photography’s rather tentative status as an art form, or about the merits of any given photographic image, can be stimulating and insightful if tempers are controlled. In that sense the spirited bull-sessions that we enjoy so thoroughly are both valid and valuable — as long as they deal with concepts, and keep opinions from masquerading as facts. After all, facts aren’t really “facts” unless they’re factual, and in that case there’s no point in arguing about them. For sonic reason, though, we seem to love to imbue every aspect of this medium with mystery so that the distinction between fact and fancy tends to blur. When that happens it’s really counterproductive.

Unlike the other visual arts, photography straddles the fence between the separate areas of art and science. The part of photography that deals with subject selection, visualization interpretation expression, and image appraisal, is clearly subjective. These are aesthetic considerations. They have no valid laws, nor any binding criteria. In this unrestricted area, opinion, whimsy and self-expression rule. Science has no business here.

On the other hand, the part of photography that involves such things as hardware function and materials’ characteristics, is rigidly governed by physical and chemical laws that are not debatable. This is the scientific realm. These things can be measured and their characteristics identified, Rumor, conjecture, superstition, and wishful thinking have no business here.

Of course we’re certainly entitled to our opinions about the suitability of the tools and materials we choose to use, but the fact that we may like or dislike a certain film, for example, is objectively irrelevant, and does not in any way affect, or necessarily even relate to, that film’s actual characteristics, Unfortunately it’s tempting to overlook this and make rash pronouncements about materials’ characteristics, based on simple observation of print results or on haphazard, experimentation; which strongly suggests the possibility that those conclusions will be misleading and that the materials may not behave as expected when used in the field.

To avoid these unpleasant surprises, many photographers — especially those who choose to work in black-and-white with large-format cameras — test their materials in one way or another Most follow the traditional zone system test methods that involve in-camera exposure of the test films, more or less arbitrarily assigned film development times, a standardized printing method, and eye-match appraisal of the print results.

When done with care these tests can provide general guidance for the field use of the materials, but these empirical methods are neither very reliable nor very efficient for a number of reasons: for example, there’s no convenient way to calibrate the individual increments of film exposure with any accuracy. In addition, although visual appraisal of print grays can provide some indication of the overall effect of the processes, it doesn’t permit very reliable analysis of the characteristics of the individual materials. In other words, we’re not likely to know for sure what we’ve done to the materials, nor can we know for sure how they’ve reacted. Finally of course, this approach to testing is very wasteful of both time and materials.

Traditionalists defend this testing method — some vehemently — on the grounds that involving the camera in the test simulates the conditions of practical use and is, therefore, not only convenient but desirable, Similarly, they are apt to argue emphatically that, after all, the purpose of this whole thing is to produce prints, so appraising print values must therefore be the most appropriate way to judge the materials’ performance.

In fact, that’s a technical non sequitur. These traditional testing procedures can’t supply material-specific information any more than driving your car around the block can inform you about the comparative quality of your motor oil, You can obviously tell whether the car runs satisfactorily or not, but you can’t know for sure what part the oil has played in that performance. There are simply too many unrecognized or uncontrolled variables in the procedure; there is no accurate way to quantify the results of such subjective tests, and you have no logical basis for assuming that the conclusions drawn are valid.

The one feature that makes the traditional test procedure) as reliable as it is, is the “standard printing time” convention. By eliminating print exposure as a variable in the process it becomes possible to "measure" negative minimum density (approximately) so that some estimate of effective film speed can be made; and it standardizes the print image densities sufficiently so that it’s possible to get a ball-park estimate of the effects of film development variations. In other words, the "standard printing time" and eyeball comparison of print grays combine to serve as a sort of make-shift densitometer. This ingenious concept made it possible for Ansel Adams to introduce into the photographic process a degree of control and predictability that was ahead of its time; and it has served a great many photographers very well.

But times change and facilities improve. No doubt many photographers will remain convinced that the popular zone system test methods are "perfect" (as one staunch traditionalist has declared), but we can now get more accurate data — and much more of it — in much less time, with minimum waste of materials, by isolating the materials tests (to eliminate a variety of uncontrollable variables) and reading the resulting test samples, objectively, with densitometers.

Although densitometers were virtually unobtainable in Adams’ day, and are by no means standard items of equipment in most darkrooms even yet, they are increasingly available on the market and prices are coming down, It’s even possible to adapt most spotmeters to make useful density readings; so almost any competent photographer can now benefit from the efficiency economy and reliability of objective testing, even on a severely limited budget.

"Knowledge is power," they say. There’s no doubt that more accurate information about how materials behave in use can be helpful; and this goes well beyond the simple calculation of more precise exposure or development times.

For example, when we can identify image gradation differences that may be produced by various combinations of materials, we have sensible criteria For choosing the film, developer, and paper that will complement each subject type most appropriately. We can even determine when "misuse" of some material — such as abnormal exposure and/or development of the film — may have useful potential, and deliberately apply it to emphasize some desirable quality of the image, These are subtleties of control that the traditional empirical testing procedures can’t provide.

I’m well aware that many photographers will disagree with me, and insist that objective testing methods dehumanize the process, inhibiting creativity and stifling freedom of expression. But I believe the opposite is more likely to be the case; better understanding should really expand creative options and lead to greater freedom, not less. Certainly knowing what your materials can or can’t be made to do should make visualization easier and more effective, and minimize the possibility of serious miscalculation.

Ultimately whether we like it or not, we can’t avoid contact with technical details in photography, so why fight it? Let’s put science to good use in the service of our art, not in conflict with it. Objective testing frankly acknowledges the existence of the two faces of photography — the technical and the aesthetic — and clarifies the distinction between them to reduce confusion, improve control, and increase efficiency. It’s hard to see why any thoughtful photographer should object to that.

Phil Davis is a teacher, author of several texts and articles on photography, and holds workshops involving sensitometric techniques. His book Beyond The Zone System outlines a basic set of sensitometric tests that accurately and quickly evaluate photographic materials.

© 2002 Phil Davis