3. MAKING THE SEQUENCE OF TEST PRINTS
Because of the negative's extreme contrast, a simple "straight" print will
have in it only a portion of the information which is contained in the
negative: the highlights or shadows (or both) will be lost. In the next two
steps of this process, I make a series of straight prints at varying exposure
times and then select from each the areas which I wish to be included in the
final image, excluding areas in the prints that are too light or too dark.
I make a series of test prints, starting with a print of short exposure
having maximum detail in the least dense areas of the negative and ending
with one of rather long exposure with good detail in the negative's densest
areas. For Pt/Pd and other processes requiring negatives of high contrast,
each exposure should be 1.4x longer than the previous. The series of
exposure times using this factor conveniently works out to be the f-number
series--2 min, 2.8, 4, 5.6, 8, 11, 16--which most of us had burned into our
brains decades ago and thus is easy to remember. For processes requiring
flatter negatives, such as gelatin silver or gum, I would use a factor of
1.2; the exposure sequence will be the f-stops with the intermediate half
stops--4, 4.8, 5.6, 6.8, 8, etc.
The printing time for the darker prints can be long. For a negative which is
"optimal" for Pt/Pd (i.e., DMin = ~.30, DMax = ~2.10), with my UV light the
exposure is 4 or 5 minutes; but, my test prints for highlight detail may run
to an hour or two with negatives which were intentionally overexposed to get
detail in even the deepest shadows.
I leave a 1/2" to 1" border around the prints. I sometimes need the border
to hold the print together after I've cut several holes in the print to make
the multilayer composite proof described below.
Depending on the contrast range of the negative, I end up with 2 to 8 test
prints. All of these are be far too contrasty, with large areas of washed
out highlights or black shadows. But (hopefully!), within each print there
are areas in which the tonal values are pleasing, often with a tactile sense
of texture due to the high local-area contrast. There is also excellent
separation of tones in shadow and highlight areas in the prints at the
extremes of the sequence.
High local-area contrast throughout the print is perhaps the single most
important goal of this process. It leads to a paradoxical effect with the
platinotype: the matte surface and inherent lack of extremes in DMax and
DMin give the overall feeling of softness which we value in these prints,
while the high local-area contrast provides a sense of snap and sharpness
which is difficult to achieve with the usual Pt/Pd printing methods.
4. CONSTRUCTING A MULTI-LAYERED PROOF FROM THE SEQUENCE
OF TEST PRINTS
The next step is to make a single proof out of this sequence of prints. I
make a multilayer proof, using only those portions of each test print which
have tonal values that I want in the final image. I will then use this
series of test prints as templates for making masks on clear acetate or
glass.
To make the multilayer proof, I start with the test prints having the
shortest exposure time. I find the first print in the sequence that has
whatever level of detail I want in the least dense portions of the negative
(which will usually be areas in deep shadow). This print (P1) will become the
first layer in the multi-layered proof.
Then, I take the next test print (P2) in the sequence. The darker tones
which were optimally printed in P1 will be too dark in P2. With scissors or
a small knife, I cut out the areas in P2 which are too dark, leaving behind
all areas which are either optimal or too light. If possible, I make the
cuts along lines in the image which make no visual sense: for example, I
will make an irregular cut through the foliage of a tree rather than through
the junction of a tree with its background. The effects of the masks in the
final print are usually completely inapparent if the outlines of the masked
areas are so chosen.
Next, I tape P2 on top of P1. I then have an image which is the composite of
these two test prints.
I continue with the remaining test prints, cutting out the areas in each that
are too dark and taping each successive print on top of the aggregate of the
earlier prints. The final print on top of the stack will consist primarily
of light tonal values. In the later stages of the process, the cutting often
results in some layers having free-floating bits dissociated from the rest of
the layer; a little transparent tape solves this problem.
The final result of this effort is a multilayered proof; it is a composite of
the test prints and a demonstration of how the final print will look after
I've made and used a set of masks. If I don't like how the composite proof
looks, I will reconstruct the original set of test prints with tape and
repeat the process; or, I will make a new set of test prints and construct a
second proof.
Being a compulsive person, I have been known expend too much energy trying to
fine tune an image to the nth degree; a bit of self-control is needed on
occasion! As I will explain in the next section, I can't control individual
separate regions smaller than 5 or 10 mm across; this limits to some degree
how much I can manipulate the tonality of small zones in the print. Also, I
have some room for adjustment in the final printing process, by varying the
exposure time under the individual masks.
For those who want shadows or highlights with no detail in the final print:
that is certainly one of your choices. I prefer to record detail in all
areas of the negative, but there is no reason tht I must include detail in
all areas of the print. The masking technique allows me to choose how each
individual area in the image is to be printed; and I can, for example,
completely burn in the shadows in a particular region if for aesthetic
reasons that is the result I want.
5. GENERAL COMMENTS ABOUT HOW THE MASKS ARE MADE AND USED
The individual test prints will each become the template for a mask. Before
I describe in detail how I make the masks, I'll describe in general terms how
the masking process works. Here are the essentials:
A mask is a sheet of acetate or glass which is painted black in the areas
which are to be shielded from further exposure. The advantages of a clear
base with black paint vs. cutouts of rubylith or black paper are several: the
masked areas don't have to be contiguous, it's quicker to paint than to cut
out, and registration of the painted masks over the print is simpler.
For most of my work, I have used plate glass rather than a flexible
substrate. Clear acetate works well and is easier to store; but, I have some
concern that over many years the black paint could become brittle and flake
off a flexible base.
Each mask consists of all areas included in the previous masks plus new areas
not included in any of the earlier masks. As long as the outlines in each
mask don't duplicate those of earlier ones, the shadows cast at the junction
of masked and unmasked areas are inconspicuous. If two or more successive
masks have identically masked areas, these shadows may become noticeable.
This becomes a problem in areas where brightly illuminated areas are
immediately juxtaposed to dark areas in shadow; hence, my comments earlier
about choice of subject matter and lighting.
Here is how the masks are used. I place the negative and coated paper in the
contact printing frame in the usual manner. Then, I place a mask on top of
the glass of the printing frame in registration with the negative, and put
the entire apparatus under the UV light source.
The painted surface of the mask must be separated from the print surface by
1/4" or so. If the frame glass and mask don't have that cumulative thickness,
a piece or two of window glass (which in the US is about 3/32" thick) can be
used as a spacer to get the desired distance.
VERY IMPORTANT: It is ***essential*** that the UV light source have a
soft, diffuse output, so that the edges of the masked areas cast soft shadows
on the print surface. A bank of closely spaced UV fluorescent tubes is
ideal. If the UV light approximates a point source (e.g., a mercury vapor
lamp), its output can be made diffuse by placing a piece of ground glass on
top of the printing frame / mask combination. For contact printing on
gelatin silver paper with an enlarger as the light source, a sheet of
milky-white plexiglas on top of the printing frame does the job
(Incidentally, this is the arrangement I use for making contact
interpositives and new negatives on film).
Because the painted areas on the masks cast shadows with very soft edges,
mask registration isn't nearly as critical as it is with such processes as
dye transfer and Ilfochrome. The first paragraph in the next section
explains how registration is accomplished.
***** End of part 2 *****
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