Resolution of CCTV systems

[gurinder dhiman]

The resolution of CCTV system is usually measured by TV lines in the
field. The vertical TV lines has maximum 350 TV lines in 525-line NTSC
system and is not variable. But the horizontal TV lines, which is used
as the parameter of picture quality, vary depending on the quality of
camera, lens, transmission and monitor.

Camera Resolution
The industry of CCD video camera sensor uses pixels (picture elements)
as its quality parameter. Medium resolution of B/W camera in EIA
system is 510 horizontal pixels by 492 vertical pixels and is
equivalent to 380 TV lines. High resolution is 768(H) x 492(V) pixels
and equivalent to 570 TV lines. Color camera's medium resolution means
330TV lines and high resolution needs more than 460 TV lines.

Monitor Resolution
The monitors in NTSC system have 525 vertical scanning lines
regardless of their size. The horizontal 700 TV lines of B/W monitors
represents medium level and more than 900 TV lines means high
resolution in EIA system. The color monitor's horizontal resolution of
300 TV lines means medium quality and that of more than 450 TV lines
means high resolution.

To maximize the system's resolution, it is recommended to choose a
monitor which has better resolution than that of the camera.