block that visible light. The most common is the
red #25, which still allows the passage of enough
visible light to use the viewfinder of a SLR camera.
Yellow and orange filters can also be used, even if
with a slighter effect. A #29 dark red filter will give
a stronger effect than the #25, however, there are
filters like the #87 and the #89 that are opaque to
visible light, giving the strongest effect. As only
infrared light is recorded on film, these are not
widely used in pictorial photography.
The typical look of an infrared photograph lies
in the facts that the objects reflect infrared light in a
different way than they do in visible light. Skies are
rendered very dark with white clouds, foliage is
much lighter than it appears to the eye. Fair skin
tones and lips appear lighter, but eyes appear very
dark in black and white infrared photography.
With Kodak Infrared, highlights will appear with
great halos or flares due to the lack of anti-halation
backing on the film. There is a popular idea that
some kinds of cloth will appear transparent to
infrared radiation but a picture where a dressed
person appears to be undressed has yet to be made.
Color infrared film is easily recognizable by its
artificial colors. The use of yellow and orange fil-
ters is advised, and infrared reflecting objects will
be rendered as red or magenta.
Some electronic image equipment seems to have
no difficulties dealing with infrared, and some video
cameras and digital still cameras are capable of
producing images in the infrared part of the spec-
trum. They are now used as preview devices or to
produce a final image. They are able to take away
some of the unpredictability of infrared photogra-
phy. However this unpredictability is part of the fun
in photographing the invisible.
NUNOPINHEIRO
Seealso:Astrophotography; Film; Filters; Infrared
Photography; Light MeterFurther Reading
Paduano, Joseph. Infrared Nude Photography. Buffalo:
Amherst, 1994.
White, Laurie.Infrared Photography Handbook. Buffalo:
Amherst, 1995.FILTERS
A filter is a transparent, often colored piece of glass
or plastic that is placed over a camera lens to pro-
duce a particular effect. Filters function as a barrier
in front of the film, changing the characteristics of
the light passing through it.
Filters are used in photography for a wide variety
of reasons, including contrast control and color cor-
rection, as well as special effects and applications.
Larger filters are also used in other ways, such as to
provide safelight illumination or to otherwise change
the color and intensity of a light source. Filters are
also used to produce special effects as well as en-
hance the effects of certain wavelengths on film.
The Behavior of Light
Light is composed of three colors: red, green and
blue. These are known as the additive primaries.
The combination of these primaries produces all
the variations of color.
Light that strikes the surface of an object can be
reflected, absorbed, or transmitted. Objects appear to
be certain colors due to their transmission or reflec-
tion of different wavelengths of light, producing
color. Black objects non-selectively absorb most of
the light falling upon them, while light and white
objects reflect the majority of the light falling on
their surface.
Filters work by reflecting, absorbing, or removing
part of the light entering the camera lens. Filters
cannot add anything to the incident light; in order
for a green filter to transmit green light, the green
wavelength must be present in the light to start with.Types of Filters
Filters can be classified by how they remove or re-
flect radiation. In the case of color filters, the
wavelength is removed selectively. For example,
a green filter absorbs red and blue, but transmitsFILTERS