Television Production and Lighting

Television Production and Lighting

Television is a means of changing patterns of light into electrical signals for
storage or transmission and then recreating those patterns on a screen. In
order to do this well, the television camera must be presented with properly
lighten scenes. There are three important things in reference to lighten the best.
i. Level
ii. Contrast range
iii. Color temperature.

i. Level
Lighting levels can be adjusted by the adjustment of the incidental light that is entering the scene, that light is touching the subjects in the scenes.
The incidental light is measured in foot-candle, that is the amount of light produced by a candle at a distance of one foot.
For high-quality pictures you need something between fifty and two hundred-foot candles. Most cameras can be operated in light ranging from the minimum up to 10,00 foot-candles. The lighting range of the cameras is almost written on the shell of the camera, e.g .19 candles or .39 candles etc. When you see that lighting range in the scene is out of the ranges of the camera you should try to adjust it. Basically this all is because of the incidental lights, so adjust it. If there is too little light, you should add additional lightings. And if there is too much incidental light coming in the scene, then you are to use special neutral density filters on the camera.

   ii.  Contrast
Contrast refers to the difference in brightness from the darkest parts of a
Scene to the brightest. The amplitude of the video signal determines useful contrast for television.
Common digital video signals are 24-bit color, with eight bits each for red,
green, and blue. This allows for 256 individual shades from dark to
light for each color. So 24-bit color allows all colors to be shown.
If contrast is low many receivers will produce a flat picture which do not clear the scene’s details. If contrast is much high details in the brightest and darkest parts of the picture will be lost. then Picture will look too heavy and colory that we be not ready to watch the detail of the scenes.So contrast is actually light reflected from the subject.

iii. Color Temperature
The third thing is color temperature. Every source of light has a
Characteristic color. This color is related to its "temperature." Lower color
Temperatures tend to be red or orange while higher temperatures tend to be
green or blue. Color temperatures are measured in degrees Kelvin
Temperature Source Color
1950 Candlelight Orange
2870 Normal Incandescent Orange
3200 Most Photo or TV Lights Orange
3400 Some Photo Lamps Orange
3500-4000 Fluorescent Lamps Green
5500 Midday Sunlight Blue
                                            (R.Inman And G.Smith, 1996)
The eye "remembers" how things are supposed to look and interprets color
accordingly, regardless of the color temperature of lighting sources. A white
sheet of paper seems white whether viewed under an incandescent lamp or
Sunlight. The eye can even adjust for "correct color" when two light sources of different colors are present in the same scene. Sunlight streaming into a
room which is also lit by incandescent lamps doesn't make objects it strikes
appear bluish.