Films, Continued
Film emulsion
definition
(Continued)
Color film
balance
Film handling
Film date
expiration
Film storage
ACUTANCE: Acutance is the objective measure of the ability of
photographic material to show a sharp linear demarcation between contiguous
areas receiving low and high levels of exposure to light.
Color film balance is the acceptable relationship among the three color
primaries in positive color prints or slides. In other words, if the color
appears correct, the color is visually balanced. Color films are referred to as
daylight (outdoor) or tungsten (indoor) film indicating their broad use without
filters. Daylight film is specifically balanced for use in sunlight or with
electronic flash. Tungsten films are balanced for use with artificial
illumination from camera or copystand lights. Using the wrong color balance
film will make slides and prints appear off-color.
Handle film only by the film edges to minimze fingerprints and the build-up
of static electricity, which appear on prints as white (undeveloped) areas.
Keep film in its protective package or canister until needed. Protect film
surfaces from dust, lint, fingerprints, abrasions, and scratches.
Films are manufactured to provide optimum color balance when purchased.
That is when a film is said to be fresh. Film emulsions are made up of many
different chemicals that deteriorate slowly over time. From the day of
manufacture, all films begin to change; and as films age, film characteristics
change. Manufacturers mark expiration dates on film packaging to indicate
when film is no longer fresh. Film is intended for prompt processing to
prevent any significant shift in color balance before development.
Store film as a first-in first-out product and refrigerate, if possible. Use film
with near expiration dates first. Refrigeration keeps film near the optimum
color balance, retarding deterioration, until used. Remove film from
refrigeration approximately 90 minutes before loading into a camera.
Allowing films to attain room temperature will prevent brittleness and
cracking. It will also prevent condensation from forming on film surfaces
that may fog pictures taken before the film has a chance to warm.
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