and fixer solutions. But there also are automatic processors available to do the
job. The most common type, called roller-transport, contains trays of solution.
You place the exposed paper into a slot on one end of the processor. Rollers
pick up the paper and automatically carry it through a series of chemical solutions
until it comes out the other end, fully developed and (on some models)
washed and dried. While these processors are convenient, they typically require
a lot of maintenance. Also, they can only process RC printing papers; they can’t
process fiber-based papers.
Part V: Determining Print Exposure
Once you’ve processed the test strip, examine it carefully to determine the best
exposure for the final print. You will find that some tests are more useful than
others, depending in large part on where you’ve positioned the test strip. The
section of the image that shows on the test should be an important part of the
overall picture, such as skin tone in a portrait subject. It also should contain a
good range of light and dark areas.
The light by which you view the test also is important. It shouldn’t be too
bright or too dark, and it should be positioned at a slight angle to the print; if
directed straight at the print, the light may be too bright for an accurate evaluation
or cause glare that makes it hard to see subtle tonal values.
The finished test strip should have a range of five exposures (or however
many exposures you gave it). The best tests are too dark on one end and too
light on the other, with the sections in the middle showing a range of print
densities. However, its is not uncommon to get a test strip that is too dark or
too light overall. Test strips that are too dark need less time and/or a smaller
lens aperture. Try a new test with 2-second intervals instead, or close down the
lens one or two stops and test again at 4-second intervals. Test strips that are
too light need more time and/or a larger lens aperture. Try a new test with 8-
second intervals, or open the lens one or two stops and test again at 4-second
intervals.
When evaluating the test, concentrate on important and clearly identifiable
areas of the subject. Skin tones, for example, should have good detail and texture.
Blue jeans should be dark, but not pitch black, and snow should be white,
but not washed out.
Sometimes the correct exposure is somewhere between sections of the test
strip. If the 8-second exposure looks a little light and the 12-second exposure is
slightly dark, about 10 seconds is probably right. If this is the case, there is no need to make a new test strip.
light-sensitive than others), and the variable-contrast filter used, (high-contrast
filters generally need the most exposure).
These factors are sometimes controllable: You can put a brighter or dimmer
light in your enlarger or use a faster- or slower-speed paper. But the two primary
ways to control print density are by varying the exposure time and/or the aperture
of the enlarging lens to change the amount of light that strikes the paper.
Exposing paper for more time produces a denser print; exposing it for less time
makes a lighter print. Opening up the lens aperture produces a denser print; closing
it down produces a lighter print.
Note that these variables correspond to the primary camera controls of film
exposure: shutter speed and lens aperture. The same reciprocal relationship
exists; if you increase one, you must equally decrease the other to keep exposures
constant. So a print exposure of f/11 at 12 seconds produces the same results as
an exposure of f/8 at 6 seconds. As you open the lens aperture (from f/11 to f/8),
you double the amount of light traveling through and must halve the amount of
exposure time (12 to 6 seconds) to compensate.
There’s no need to save your test strip: Use it for reference until you’ve made
your final print, and then discard it. If you reprint the negative at a later time,
you will need to make a new test strip anyway, since equipment, materials, and
other conditions may change.
Once you’ve determined an exposure time, place a fresh, full sheet of paper in
the easel emulsion side up, reset the timer for 10 seconds (or whatever time
you’ve chosen), and expose the paper. Don’t change anything but the exposure
time—not the f-stop setting, easel location, image size, or focus (unless you
need to refocus because the test image is not sharp).
Develop, stop, and fix the exposed paper. Then examine the print again in
room light. The main factors to consider when evaluating the print are overall
density and contrast—and whether specific image areas need to be darker or
lighter than the whole. Pay particular attention to the print highlights and see
that they look right.
Overall density is controlled by print exposure. If your print is dense (too
dark), you will need to make a new print using less time and/or a smaller lens
aperture. If your print lacks density (too light), make a new print using more
time and/or a larger lens aperture. Making small changes to the exposure time
is generally the best way to make subtle adjustments.
Generally, correct print density means a good range of tones from light to
dark, with detail in most highlight and shadow areas. But, ultimately, correct
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