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Repro-Copying
For originals such as photographs which have tonal
gradation, exposure is determined in the usual way.
In the case of originals having strong contrast and no
gradation, such as documents or line drawings, meas-
ure brightness of the white portion of the original
(if the original is predominantly black, a sheet of white
paper may be substituted) after decreasing film speed
by four marks. Or increase exposure about 1-1/3 stops.
Slide Copying
For originals with continuous tone gradations, deter-
mine exposure in the usual way by the stop-down
method.
To copy slides with letters or figures on
transparent
background,
decrease film speed four
marks
or
increase
exposure
about
1-1/3 stops. In
the case of transparent figures or letters on a dark
background, either increase film speed five marks or
decrease exposure about 1-2/3 stops.
Important: The above are only approximate guidelines. Exact
exposure determination is extremely difficult, especially with
color reversal films, Therefore, it is advisable to make several
different exposures for each subject to be sure of getting one
|
that is correct.
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