TM 5-3610-257-14
NOTE
Very small unit changes should be made during test because the highlight dot will close up fast.
(c)
If required, make necessary adjustments to HIGHLIGHT UNITS to achieve desired highlight dot.
(d)
When proper number of highlight units have been determined, record on exposure record card.
(13)
Once time units have been determined, they become the basic time unit setting and will not change as long
as same halftone screen, film, chemistry, and developing technique are used.
h.
Basic screen range. A basic screen range test must be made for every halftone screen used, whether contact or
glass.
(1)
Using previously determined main and highlight exposures, make a test exposure.
(2)
From this test negative, determine where on gray scale a normal size shadow dot will be and record step
number.
(3)
With digital densitometer check density of step on gray scale where shadow dot was recorded.
(4)
Determine basic screen range density by subtracting density of first step (on gray scale) from density
reading obtained in step 3 above.
Example:
1.17
Density of gray scale where shadow dot recorded.
-.07
Density of first step of gray scale.
1.10
Basic density range of screen.
NOTE
The basic screen range is an important factor in determining and controlling flash exposures.
(5)
Place determined basic screen range on flash dial (3-6.3e).
(6)
Record this basic screen range on exposure record card.
i.
Flash test. The purpose of this test is to determine number of time units required with a particular halftone screen
to produce desired shadow dot.
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