TM 5-3610-285-14
(13)
At 20 seconds, move the mask to uncover another 1/4 of the film (3/4 is now showing).
(14)
At 10 seconds, remove the mask altogether.
(15)
When the exposing lamp goes out, turn off vacuum pump rocker switch.
(16)
Turn off power switch for timer/power supply control box.
(17)
Open bleed valve to bleed vacuum off vacuum frame.
(18)
Unlock the left-and right-hand latches and lift the glass frame until the two lift arms take hold and open the frame
completely.
(19)
Remove exposed contact or duplicating film and process.
(20)
Compare the processed step-off film with the original negative or positive.
NOTE
One of the steps will match the original film closer than any other step. This step may be exactly right, or
you may have to do a second step-off test with shorter intervals of time, and/or different intensity settings
to find the right exposure.
(21)
Repeat steps (1) through (20) until correct exposure controls are obtained.
(22)
Once you have found the right exposure by step-off, strip a contact control guide onto the edge of the test
halftone, and make a final contact or duplicate at the new exposure time (steps (1) through (19)).
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