What is the principle of camera day/night switching (i.e. color to black and white)?

In certain light source conditions, the use of line switching to convert the image from color to black and white. In the color / black and white line conversion technology evolution, the early use of two Sensor (1 color, 1 black and white) **** with a set of circuits and then switch.

This type of camera has a single CCD (color) design, during the day or when the light source is sufficient for the color camera, when the night falls or when the light source is insufficient (generally in 1LUX?3LUX) that is, the use of digital circuitry to eliminate color signals to become a black-and-white image, this approach can be achieved at night, although the "low illumination" purpose, but during the day, it is not the case that the color signal will be eliminated. This approach can be achieved at night "low illumination" purpose, but during the day there is a fuzzy image, the color is not natural shortcomings.

Expanded:

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Technical Parameters

Product Name, Day/Night Full Color Camera

Sensor, 1/3" SONY Super HAD II CCD

PAL:752(H) x 582(V)/NTSC :768(H) x 494(V), Scanning Mode

Interlaced, Sync Mode

Internal Sync, Horizontal and Vertical Frequency

PAL:15.625 kHz, 50.00 HZ / NTSC :15.734kHZ,59.94HZ

Sharpness, Color 520 lines

Video Output<

1.0Vp-p/75Ω composite video signal

Signal-to-Noise Ratio (SNR)

More than 50dB (with Auto Gain Off)