Controlling Black and White Films
The principal attraction of
black-and-white film is the enormous potential for control that the
medium offers. Some of the controls, such as exposure, resemble those
available to the photographer working in color, but others are quite
The first opportunity for control lies in
processing the film. Prolonging development increases the density of
the black-and-white negative overall, but the effect is more marked in
the denser parts of the image - those areas that will form the
highlights of the print. Increased development makes the highlights
much brighter, but with little change to the shadows. So by changing
the development, you can exert precise control over negative contrast.
This control over contrast continues at
the printing stage. Black-and-white printing paper is available in a
wide range of contrasts or grades, so that you can potentially make
several different prints from the same negative, simply by changing
paper. Variable contrast paper make the change even easier: you just
slide a different colored filter into the enlarger.
As with color printing, it's possible to
change the tones of any area of the black-and-white print, simply by
altering the exposure given to the individual areas of the print. You
can use this facility to hide portions of the landscape in deep shadow,
or perhaps to darken the sky several tones.