Color film also consists of a light-sensitive emulsion on a transparent or
opaque base used to record images. The main difference between color and
black-and-white films is that color emulsion consists of three distinct layers.
Each of the three layers of emulsion records one of the three additive
primaries - red, green, or blue. Modern films have fast and slow emulsion
layers for each primary color to improve film speed and resolution. Color
films produce reversals (positive) or negative images.
COLOR REVERSALS: Color reversal films produce positive images in
densities directly proportional to the objects in a scene. Reversal films
contain the suffix chrome in their name. Development of color reversal
films is a two-stage process. Developed color reversal film can be used as
transparencies (slides) for direct viewing, printed directly onto color reversal
paper, copied on black-and-white films for producing black-and-white prints,
or copied onto color internegative (copy negative) for producing color prints.
COLOR NEGATIVES: Color negatives record scenes in image densities
opposite to the brightness of objects in a scene. Most color negatives have an
orange mask that increases color separations producing colors more
accurately. Color negative films contain the suffix color in their name.
Color negative images can be printed on color positive materials such as
color-paper and color-print film to produce color prints or transparencies.
Color negatives can also be printed on special panchromatic black-and-white
paper to produce black-and-white prints.
The two basic film formats commonly used in the Navy are roll film and
sheet film. Both formats come in a variety of sizes. Both film formats are
available in black-and-white or color.
Roll film is film packaged so that it may be loaded and unloaded from a
camera in daylight. Number 120 roll film has a paper backing that prevents
inadvertent exposure; 35mm film is wound in light-tight cassettes. The most
common film size, 35mm, comes in prepackaged cassettes in lengths
producing 12, 20, 24, and 36 exposures or frames per roll. Also, 35mm film
comes in 100-foot rolls for bulk loading into reusable cassettes.
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