Video signal used in CCTV is called VBS (video, blanking &syncs, or video baseband signal) and CVBS (composite/color video baseband signal).

VBS is composed of synchronization / blanking impulses and luminance information, CVBS additionally comprises chrominance information. Luminance carries information about image brightness, chrominance informs about colors in the image. Synchronization impulses are in fact combined signals of horizontal and vertical deflection, which synchronize monitor with the camera.

The standard composite video signal has 1V_p-p amplitude (peak-to-peak). The impedance of each device processing video signal should be 75 ohm. It is standard value commonly used in television/video technology, so that it is possible to use some universal devices. The example may be the use of video cassette recorder, or real-time monitoring on regular TV set equipped with audio/video input. Of course, use of consumer electronics equipment in professional CCTV installations is generally not acceptable. They do not guarantee continuous operation nor the optimum quality.

Applied standards
Due to accepted principles and image quality, the frequency range of video baseband signal is 25 Hz to at least 5.0 MHz. The set of all parameters of video signal is called a television standard. The standard defines, among others, polarization, number of TV lines (TVL), image frame rate, horizontal scanning frequency, vertical scanning frequency, channel raster, video signal bandwidth and frequency of audio carrier. Analog CCTV systems usually do not use audio features.

The standard accepted in Poland is D/K, however in West Europe it is B/G. With regard to video signal parameters, the both standards are practically the same. Generally, but not quite correctly, the B/G standard is called CCIR, and the D/K - OIRT. In the United States and in Asia there is used different standard called EIA or NTSC. Cameras using this standard are not suitable for work with European devices.

Parameters of color image are defined by color television system. By reason of ensuring compatibility with B/W imaging, it has been decided that information about the color will be contained in some part of the spectrum of luminance signal, which is less important for image quality. In Poland and most European countries, PAL system has been accepted, however United States and in some Asian countries use NTSC system. Another TV system, SECAM, is not used in CCTV at all.

It should be remembered that devices used in the whole installation should utilize the same standard and TV system. The information on the standard and system is included in the manual, and usually shown on the sticker.