ExxtraSetter
Maxxima 300
OPERATOR'S MANUAL
25
5.4 Setting Proper Exposure Density
The ExxtraSetter is set up at the factory so that exposed areas of Kodak Pagi-Set IR film will measure a
Dmax (maximum exposure density) of 3.7 to 4.3 when the
is adjusted to 100%. This is an
approximation because of the varying effects of processing and different film lots. Dmax will also vary
slightly between different resolutions. Different films and papers can vary in sensitivity by as much as two
to one or more. Kodak film tends to be one of the fastest films currently available, however, the selection of
Kodak film as the reference 100%
setting is arbitrary, as is the
scale itself. If the
film that is used requires a
setting of 200%, then that setting is normal for that film.
NOTE:
Setting the
too high for a given film will degrade image
quality, increase dot gain and may produce fogging of otherwise unexposed
areas of the image.
Setting the
too low for a given film will produce low Dmax
values resulting in weak fine image details which may not reproduce in
final printed copy.
If different films and resolutions are used, it is strongly recommended that a log sheet be kept showing best
for a given film and resolution, and some evaluation of processor performance information.
This will reduce the exercise of setting up Dmax from an iteration of several film measurements down to
some minor fine tuning.
Under the
is a test called
. This test varies the laser power in
5% increments from 85% to 125% of the current
setting at the current resolution. The test
paints stripes of 100% (black) and 50% (theoretical) gray tints for each power setting. The 50% gray tint is
uncalibrated and will run anywhere from 52% to 60% depending on such factors as resolution, brand of
film, Dmax, and processing chemicals and conditions. This is normal for the given conditions. By
measuring the black stripes with a densitometer, the optimum density setting can be established quickly.
The following procedure outlines the steps in doing this:
1. Verify that the Drum has an unexposed piece of film on it and that the 'Imager is home'. If in doubt,
move the imager home
and push the Film Feed Key
to flush the drum .
2. Select the
that you wish to use from the Control panel
.
3. Select
from the control panel.
4. The imagesetter will now image the density group described above.
5. When it has completed imaging,
a) Move the imager home
,
b) Push the Film Feed key
, and when it is finished feeding the film,
c) Push the cut key
d) Remove the Output Cassette and
e) Develop the film.
5. The nine pairs of stripes on the film start at the margin at the 85% level and increase at five percent
increments up to 125% of the present set
. Measure each of the black (100% tint) stripes
with a densitometer and determine which stripe has the desired Dmax (usually around 4.0 for many
films).
