c. Use of Viewing Filters. You can use CC or CP filters to view your
A filter used to view your test tends to over correct the
highlights and under correct the shadows.
Therefore, study the lighter
middle tones while looking through the viewing filter.
(1) Do not stare through the filter; flick it in and out of your
view. This prevents the eye from adjusting to a false color that it will do
if the filter is not flicked.
(2) You may have trouble distinguishing a specific color in the
Try to think of them as "cool" (cyan, blue, green) or "warm"
(red, magenta, yellow).
(a) If you think the print looks too blue, view it through a
yellow filter, changing the density until it looks its best. If you cannot
tell cyan from blue, view the test print through red and yellow filters
until you decide which viewing filter makes the best correction.
(b) You may have a test that you think looks red and magenta. In
this case, it would appear to be corrected when viewing through both cyan
and green viewing filters.
d. Correcting the Filter Pack.
As an example, to decide how much
filtration to add to the filter pack, make a test print at 50M + 50Y. It
appears to have good overall density, but it is a little too magenta. When
viewed through green filters, it looks balanced.
(1) If the density of viewing filtration is 20G, on the next test add
10M to the filter pack. Remember the rule: add to the filter pack half the
density and the complement of the viewing filter. In this example, make the
next test with a filter pack of 60M + 50Y.
(2) To modify the printing filter pack, the information given in
figure 3-1 should prove useful in determining what filter adjustment should
The filter pack should not contain more than two colors of the
subtractive filters (yellow, magenta, and cyan).
When all three
colors are in the filter pack, the effect is neutral density (nd)
which only serves to increase the exposure time required. Neutral
density is eliminated by removing the filter color of least density
completely, and then removing the same density of each of the other
two colors. Thus, if you calculated the filter pack to be 30M + 20Y
+ 10C, you would completely remove the 10C + 10M + 10Y to give a
filter pack of 20M + 10Y +0C.