15.
Latitude.
All color materials should be accurately exposed.
Most color negative
materials have greater exposure latitude than color reversal materials.
a. Using Negative Materials. Acceptable reproductions can be made from
negative materials that deviate from the optimum exposure, especially if the
error is on the overexposure side.
(1) Negative color film can be exposed over a range from one f/stop
under to two f/stops over.
However, optimum exposure will always provide
the best results when printing color negatives.
(2) If no meter is available to obtain the correct reading and there
is doubt concerning exposure, a good rule to follow is to overexpose or
bracket the exposure.
Adjustments for exposure error can be made during
printing if the subject has been recorded on the useful portion of the
characteristic curve.
b. Using Reversal Materials.
Significant deviation in exposure, when
using reversal films, will produce a final product with unacceptable density
and possible color shifts.
(1) Reversal color films usually have an exposure latitude of one
f/stop (+/- one-half stop). More than one-half stop in overexposure results
in washed-out transparencies with reduced color saturation.
(2) Underexposure results in dense transparencies with loss of shadow
detail and a color shift.
The film data sheet furnishes information for
exposure and different lighting conditions.
16.
Color Film Storage.
The color quality of photographic emulsions is subject to change due to age,
temperature, humidity, and atmospheric elements. Improper storage can ruin
color emulsions very quickly.
a. Age. All photographic emulsions are dated. They should be exposed
and processed prior to the "Process Before" date. Although proper storage
under controlled temperature and humidity conditions will retard spoilage,
no specific extension date can be given without testing each emulsion batch.
b. Temperature.
Color film should be store d i n unop e n e d
p a c k a g e s at a temperature of 55 de g r e e s Fahrenheit (F) (13
1-29
SS0514
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