Learning Event 3:
PROCESSING IN HIGH TEMPERATURES
1.
When film is not developed for some time after exposure, the latent image is partly lost and there is a loss
of quality in the final developed image. This deterioration of the latent image occurs to some extent under all
conditions, but is greatly increased with heat and humidity. To prevent this deterioration and to minimize fog
and softening of film emulsion, develop film within 24 hours after exposure.
2.
With portable developing units such as the EH-94 and mobile photographic laboratories such as the ES-
82A and ES-38C, this should not pose a great problem.
a. If you must set up a laboratory in a tent or building, then it is imperative that a way be found to keep
chemistry at the correct temperature. For most processes, 75F (24C) is considered the upper limit for black and
white films. There are processes that can be used up to 85F (29.5C). Check the manufacturer's instructions for
high temperature processing.
b. Color film is not a problem since the normal developing temperatures for the C-41 process are 100F
(38C) for the first developer and 75F to 105F (24C to 41C) for the remainder of the process. Transparency
film process E6 requires temperatures from 92F to 102F (33C to 39C).
c. The main problem is maintaining each chemical at the required temperature.
Learning Event 4:
USING COLOR FILMS IN TROPICAL CLIMATES
1.
Film, as with equipment, is susceptible to high humidity and heat. Film that has absorbed too much
moisture can buckle or stick to itself or the camera mechanism. The following procedures will reduce this
problem.
a. Keep film in the original packing until ready to use.
b. If possible, store the film at 50F (10C) or below until ready to use.
c. Allow the film to warm up for at least one hour before removing the wrapping. This will eliminate
sweating.
d. Expose the film as soon as possible.
e. Protect the film in its original container but do not seal the film unless it can be dried. Process the
film as soon as possible and no longer than 24 hours after exposure.
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