328 THE HASSELBLAD MANUAL
Lighting
Tungsten lights or electronic fl ash, especially studio units with modeling lights, are good
choices. Lighting must be even from corner to corner and without disturbing refl ections.
For small documents, one light may be suffi cient, but two lights provide better possibilities for
larger documents. Place the lights at equal distances on two sides, far enough away to cover
the entire area and each at an angle of approximately 35 to 40 degrees. With colored walls
or ceilings, turn off all or most of the room lights to avoid the refl ection of these colors onto
the copy. Keep out daylight. Check that nothing from the room, the chrome parts of the cam-
era, the copy stand or tripod, or the photographer’s white shirtsleeve is refl ected on the copy,
especially when photographing glossy surfaces.
Polarizing the Light Source
The results when copying any type of document, picture, or photograph can be improved,
often dramatically, with polarized light by producing images with a higher contrast and better
color saturation. Polarized light is recommended for all copying, especially for photographing
shiny surfaces, glossy photographs or pictures under glass, and charts on black backgrounds.
Polarization can make the background really black and make pencil lines and other marks dis-
appear (see Figure 17-9).
Because the subjects to be copied are at a right angle to the camera axis, a polarizing fi l-
ter over the camera lens alone does not improve the results. You must also polarize the light
that reaches the copy by using fi lters over the light source(s). Tungsten lights can be used but
may create a heat problem for the polarizing material. I recommend studio fl ash units with
modeling lights as a light source. You need sheets of polarizing material large enough to cover
the lights and place them about a foot away when using modeling lights that produce some
heat. With small portable fl ash units, the polarizing fi lter does not have to be larger than the
fl ash head.
You need a regular polarizing fi lter over the lens to create what is known as cross-polari-
zation, which is created when the polarizing fi lter on the camera is 90 degrees to the angle
of the fi lters on the light sources (see Figure 17-10). A circular polarizing fi lter must be used
on lenses in the H camera system. Turn the polarizing fi lter on the camera lens while visually
checking the results on the focusing screen. You will probably see a drastic change. Leave
the fi lter in the position that produces the desired results and take the picture after making
any exposure adjustment for the polarizing fi lter on the camera. Take exposure meter read-
ings in your usual fashion. With tungsten light and a built-in meter, take the reading off of a
gray card. Consult the histogram in digital work. Check Chapter 18 when using electronic
fl ash with H cameras. Make test exposures.
QUALITY OF FILTERS
Filters used with quality lenses for critical photography must be made to the same quality
standards as the lenses. This is especially important when the fi lters are used extensively
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