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Black and white film is obsolete! Not black and white photography, just negative film. As explained in Scanning Black and White Negatives , negatives have a limited tonal range and thus fit the dynamic range of film scanners poorly, This produces images with poor gradation, unless hi-bit (12-16 bit) scans are used. Color transparency film is much better fitted to the range of the scanner with a density range of 3.0 to 4.0 rather than the range of less than 2.0 for negatives. In this tip I'll show how to produce a variety of black and white prints from a single original. This allows the creative decisions to be made after the exposure, rather than in the field. Here is the original scanned in color image. A nice white church on the Big Island of Hawaii taken on a slightly overcast day. The third column shows a color spectrum. |
Color Original |
Color Wedge Original |
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We now select just the green channel as a separate file and convert to gray-scale. This is equivalent to having taken the picture through a medium green (Wratten #11, X1) filter. Notice the overall tonality tends to match the color image. This is similar to what a standard landscape photographer would choose to render a "normal" print. Medium green or yellow (Wratten #8, K2) are usually the first choice to balance the sky to foliage. The third column shows the
spectrum under the same conditions. Note green appears white.
Real filters would not be this pure. |
Green Filter Image |
Green Channel
Wedge |
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But we don't have settle for this treatment. We could give the image an old-fashioned, orthochromatic look by using only the blue channel. The sky is lighter and the foliage darker. This would be more apparent if there was any actual blue sky showing. The clouds and the sky would merge together. The third column shows the
spectrum under the same conditions. Note blue appears white. Real
filters would not be this pure. |
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Blue Channel
Wedge |
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But maybe we're still not happy. In that case let's choose the red channel. This gives an image as if taken with a Wratten #25, A filter. Now we have the typical
contrasty sky and almost black foliage on the trees. Very
dramatic! The third column shows the
spectrum under the same conditions. Note red appears white. Real
filters would not be this pure.
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Red Channel
Wedge |
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We're still not satisfied. So we apply a curve filter to this image as shown at right. This curve is similar to what would happen if we printed on a grade 3 paper. The third column shows the
spectrum with a curve applied with a big dip in the middle of the
red tonal range. This effect is not possible with conventional
film except by making color separations and masks. Note color
distortions in the middle of the spectrum. |
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Impossible Curve
Wedge |
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Here is the resulting image. The sky is more dramatic and the whole picture is much more contrasty. This is similar to what would have happened if we had given the film additional development as is done in the zone system. So, rather than agonizing
over "previzualization" and forcing a single decision
when the image was shot, we can explore variations later on.
Maybe our original conception was wrong, maybe we couldn't
anticipate the actual effect of the exposure or filter on the
negative. In any case we have the flexibility to realize our goal
later on. Other variations using the channel mixer option in Photoshop allow for color blending of individual channel to produce intermediate results. The third column shows the previous impossible spectrum in black and white. Notice the odd tonalities. |
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Impossible
Curve Wedge B&W |
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But wait! You want a real, silver-based print. In that case, reverse the tonalities, make some curve adjustments and print out a full-sized negative on clear film. Using a resolution of 300 - 360 dpi on a modern printer will give a negative that can be contact printed onto any desired enlarging paper. And remember that all burning on dodging can be done on the negative so that the printing in the darkroom is routine, with as many identical prints made as desired. Before anyone objects too
strongly, I'll admit that there is one aspect in which
negative film is superior: latitude. The exposure range of slide
film is 4 to 6 stops compared to 8 to 10 stops for negative film
(especially if given full exposure for shadows). There is even a
solution for this, at least for static subjects. See my tip Photographing "Impossible" Lighting Conditions. The third column shows the
original spectrum set to greyscale. This doesn't produce a
very good likeness. Use the channel mixer for better
results.
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Wedge set
to B&W |
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© 2002 Robert D Feinman