FOR-A VFC-1000, Руководство по эксплуатации

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6-3. Lighting
During high-speed record, exposure time is very short — generally no more than 1/100 to
1/1000 the exposure time used with television cameras. Therefore, lighting requirements are
at least 100 to 1000 times greater.
As a general guideline, the light value requirements can be estimated by the following
equation:
(lens aperture)
2
Light Value of Subject (lx) =
2
×
shutter speed (in seconds)
(Example) If lens aperture is set to F:4 and shutter speed is 1/1000 second, subject light
value is 4
×
4/2
×
0.001=8000 lx.
This equation is merely a guideline for selecting lighting; it is not intended for
determining exposure.
Major types of lighting equipment
Halogen lamps: This is a common type of lighting. A wide variety of inexpensive
products are available, ranging from low illumination to high
illumination. Color temperature is 3000K, which is close to red.
Life is about 200 to 300 hours.
Strobe light source: These lights have high brightness, short illumination time (5 to
50 microseconds), and low radiant heat. However, they have an
illumination variance of ±10%. Strobe lights are activated by a
trigger signal from the camera. The light value declines at 500
Hz or more of continuous lighting.
Metal halide: Metal halide lights are well suited to high-speed recording as a
super bright cool light source. They can provide a light value of
1 million lx or higher. In addition, they have a long life (2000
hours), but are expensive.