(1) Positioning the copy. After the "ready" light has come on,
move the copyboard back until it rests in a horizontal position (figure
28). Open the copyboard by squeezing the latch together and lifting
the copyboard glass until it rests against the copyboard rest pad. Then
center the copy with the appropriate guide markings. You then close the
copyboard glass, ensuring the latches lock into position over the
copyboard frame, and move the copyboard to its vertical position.
(2) Setting the enlargement or reduction. With the copy in place,
you must set the camera for any reduction or enlargement.
(a) You can use a proportion rule (scaling wheel) to determine
the correct scale setting for the reproduction size required (figure 2
9). A scaling wheel has two independent scales mounted at a common
center. You can use this scale to determine the reduction or
enlargement of a copy in either a percentage or linear (inches, feet,
(b) The proportional scale has a range from 25 to 300 percent.
To determine the change in a percentage, align the