e. Black and White Graphics.
When you consider a graphic, your
initial reaction is the colors black and white suit almost all forms of
graphics, especially if the graphic presents a mathematical function or
formula that would benefit from the extreme contrast between black and
white. However, this does not apply to graphics for television.
(1) When there is too much contrast (when the two extremes are
next to each other), it could cause halos and horizontal streaking. The
best way to present this graphic is with three different tones.
As an illustrator you might consider it inappropriate, but you must use
some black and white in graphics.
The video engineer sets the video
levels on a black-white basis. Therefore, he must have black and white
present in the graphic to establish his basic video setup.
(2) After properly adjusting a black-and-white television, there
are approximately eight different shades of gray, besides black and
white.
Unfortunately, transmission restrictions limit the number of
these shades available for use, and you must use the shades carefully.
You cannot place two slightly different shades of gray side by side
because they probably will appear the same. You should limit your black
and white graphic to no more than three different shades for gray,
besides black and white. When using only three different shades of gray,
you can use every other shade of gray.
f. Color Graphics for Black-and-White Television.
When preparing
color graphics for black-and-white television, you must select the colors
cautiously, and only use them in their gray scale equivalents. You must
remember that two colors may present a considerable contrast to the eye,
but when seen on television, they appear as the same shade of gray. If
you have any doubt about whether the colors are presenting a contrast on
television, check them on the camera prior to designing the graphic. Do
not fall into the trap of believing that somehow colors enhance this type
of graphic, since they may not.
If for some reason you do use colors for a graphic black-and-white
television, you should prepare and use a gray response chart.
When
designing and constructing the graphic, use the gray response chart as a
reference to determine the contrast each color will present when seen on
television. To construct a gray chart, lay out the gray scale and then
make on-camera comparisons of the colors you intend to use. You may not
find an exact shade of gray to match the hue of the color you chose for
the graphic.
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