CAMERA FILTERS ©
Ira Tiffen
3
difference in the readings is the compensation needed for that filter. You could also use a
spot meter, reading the same bright patch, with similar results. There are some exceptions
to this depending on the filter color, the meter sensitivity, and the target color, but this is
often better than taking a guess.
Filter Grades
Many filter types are available in a range of "grades" of differing strengths. This
allows the extent of the effect to be tailored to suit various situations. The grade numbering
range can vary with the effect type, and generally, the higher the number, the stronger the
effect. Unless otherwise stated, there is no mathematical relationship between the
numbers and the strengths. A grade 4 is not twice the strength of a grade 2. A grade 1
plus a grade 4 doesn't add up to a grade 5.
CAMERA FILTERS FOR BOTH COLOR AND BLACK-AND-WHITE
Ultraviolet Filters
Film, as well as video, often exhibits a greater sensitivity to what is to us invisible,
ultraviolet light. This is most often outdoors, especially at high altitudes, where the UV-
absorbing atmosphere is thinner; and over long distances, such as marine scenes. It can
show up as a bluish color cast with color film, or it can cause a low-contrast haze that
diminishes details, especially when viewing far-away objects, in either color or black-and-
white. Ultraviolet filters absorb UV light generally without affecting light in the visible region.
It is important to distinguish between UV-generated haze and that of air-borne
particles, such as smog. The latter is made up of opaque matter that absorbs visible light
as well as UV, and will not be appreciably removed by a UV filter.
Ultraviolet filters come in a variety of absorption levels, usually measured by their
percent transmission at 400 nanometers (nm), the visible-UV wavelength boundary. Use a
filter that transmits zero percent at 400 nm, such as the Tiffen
Haze 2
, for aerial and far-
distant scenes; the Tiffen
Haze 1
, transmitting 29% at 400 nm, is fine for average
situations.
Infra-Red Filters
Certain special situations call for the use of black-and-white or color infra-red
sensitive films. For aerial haze penetration, recording heat effects, and other purposes
they are invaluable. Their color and tonal renditions are very different, however, from other
film types (consult film manufacturers for further details). Various filters are used to reduce
unwanted visible light. Red, orange, and yellow filters, as used for panchromatic black-and-
white film can enhance contrast and alter color. Total visible light absorption transmitting
only infra-red, as with the Wratten
#87
or
#89
series of filters, can also be useful. The
results will vary with film type and other factors. Prior testing for most situations is a must.
Neutral Density Filters
