b. The television camera can tolerate only a limited difference between
the lightest and darkest areas of a scene if it is to show the subtle
brightness differences in the dark picture areas, the middle range, and the
light picture areas.
(1) When working with contrast, the primary concern is the amount of
light reflected by the colors and various surfaces reflecting the light, rather
than the amount of light being emitted by the lighting instruments themselves.
For example, a white object, such as a refrigerator, will reflect a great deal
more light than a dark-blue velvet cloth, even when they are illuminated by the
same light source.
Further, if you should place a highly polished piece of
brass on that same velvet cloth, you would probably have too much contrast
without even beginning to light.
(2) The difference between the lightest and darkest parts of a picture
is known as the contrast ratio. For most color television cameras, the primary
contrast ratio is 30:1. This means that the lightest part of the picture area
is 30 times as bright as the darkest picture area. If the contrast ratio is
more than 30:1, the camera can no longer reproduce the subtle brightness
differences in the lightest and darkest parts of the picture area.
(3) There are three general ways to keep the contrast ratio within
television's 30:1 limits. If you follow these guidelines, you should be within
the contrast limits of your equipment.
(a) Stay aware of the level of reflectance of objects.
A highly
reflective object needs less illumination than a light-absorbing object.
(b) Avoid high brightness contrasts in the same shot. For example,
instead of placing a highly polished piece of brass on a dark-blue piece of
cloth, place it on a more light-reflecting piece of cloth.
(c) Lighten the shadow areas with fill light. This will help to show
some of the detail that otherwise might be lost because of too high a contrast
ratio.
7. Aesthetic requirements pertain to the artistic value of a scene.
To meet
these requirements the following points must be considered:
a. Producing a pleasing picture by the proper distribution of light and
shadows.
b. Support the illusion of reality such as moonlight, sunlight, or other
similar settings.
c. Help bring out the depth and dimension of a scene.
d. Add beauty and glamour to the talent or subject.
e. Enhance the actors' looks by bringing out the good side of their
features and playing down objectional ones.
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