JVC VideoMovie GR-C7 Manual De Instrucciones página 33

SUPPLEMENTAL INFORMATION
What is "colour temperature'?
Light is composed of various colour components in different
proportions. A relationship exists between the temperature
of a light source and the colour components of the emitted
light; as the temperature rises, the colour of the light varies
from red, orange, yellow, white to blue in that order. "Colour
temperature' is a value that expresses differences in colour
among light sources, measured in Kelvin degrees. Bluish tight
has a higher colour temperature than reddish light.
What is "white balance''?
Making the colours look natural on TV is what white balance
is all about, Because a camera is not as adaptable as the
human eye, if a light source is reddish, white subjects in that
light are recorded as reddish. White balance adjustment is
performed to compensate for colour temperature variations
of light so that whites are reproduced as white. Correct white
balance makes all other colours correct. The GR-C7E can
perform automatic white balance adjustment in the full-auto
mode. However, if illumination is insufficient, white balance
adjustment cannot be performed. To obtain correct colours,
therefore, sufficient illumination is essential.
What is "'illumiance''?
"Niluminance" (also called 'luminance') is the intensity or
brightness of light, expressed in lux. The GR-C7E is designed
to provide best pictures under the conditions of a 700-lux
illuminance, although shooting is possible all the way down
to 15lux. To obtain good pictures in very bright light, the
use of an ND (neutral density) filter is recommended. See
chart on this page.
How to get good colour pictures
The simplest way is to provide sufficient lighting (close to the
camera's reference illuminance) and accurately adjust the
camera to the colour temperature of that lighting. If light
sources of different colour temperatures are used together,
accurate white balance adjustment is very difficult. For
example, if natural light is mixed with artificial light, which is
likely to occur next to windows, correct colours of the sub-
ject are difficult to obtain, It is recommended in such cases
that curtains in the room be closed to shut out light from
outside, Also, when artificial lighting devices are used, they
should atl have the same colour temperature. For example,
it is recommended that incandescent or halogen lamps not be
used together with fluorescent lighting.
Colour temperatures of various artificial lighting
Fluorescent lamp
Mluminance chart
®The values on this chart are approximated to give you a
rough reference.
Unit: Lux
ND filter desired
e Clear sky, mid-day, under
sunlight (100,000)
© Clear sky (10:00 a.m.) under
sunlight (65,000)
© Clear sky (3:00 p.m.) under
sunlight (35,000)
@ Cloudy sky (mid-day) under
sunlight (32,000)
@ Cloudy sky (10:00 a.m.) under
sunlight (25,000)
@ By the window during the
afternoon (3,500)
Range for practical use
@ Cloudy sky
(one hour after sunrise) (2,000)
© Clear sky
(one hour before sunset) (1,000)
® Counters at department stores
(500 — 700)
® Bowling centre (500)
© Office under fluorescent light
(400 — 500)
@ Library (400 — 500)
e Direct light of a flashlight at
1 m distance (250)
Lighting desired
@Streetlights at night
(150 — 200)
Minimum
lighting for
an object
15-4 e Cigarette lighter
(at a distance of 30 cm) (15)
10-41 Candlelight
(at a distance of 20 cm) (10 — 15)
Lighting necessary