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Guide to Closed Circuit TV (CCTV)

So would you like to play "Spot the CCTV Camera?". Eagle eyed visitors may recognise the profusion of street furniture, surrounding a single heritage dome camera keeping watch over part  of Londons' prestigious Oxford Street shopping area.

They say a picture is worth
a thousand words ....

Conventional (CRT) Colour Monitors - continued

Some of the better quality models have two or even three video inputs available, often with S-Video (4 pin Y/C “Super VHS” connectors), and all with looping inputs, allowing further connections to be made to additional equipment such as a ‘Master Monitor’ recording VCR, or Digital Video Recorder.

Most larger monitors (above 14”) will normally have an audio facility as standard, and many will offer playback from other international television standards (PAL / NTSC / SECAM) provided of course you have a suitably capable video player!

Occasionally, you will come across a unit fitted with an ‘Underscan’ switch (also found on a few better quality Black and White units), which usefully allows the picture to be compressed by about 10% - 20% so that you can see everything that the camera is producing, right to the edge.

This can be quite an advantage, particularly if a video recorders Time and Date display is partially obscured, simply because it’s been positioned on the edge of the image (a common problem when playing back recordings made on another CCTV system).

As well as providing a robust well mannered unit, most metal cased colour monitors can be stacked into a small display matrix, but always remember that heat is the major killer; so take special precautions to make sure that the components are not being ever so gently cooked at a constant high temperature.

The one major problem with all CRT based monitors, and it has to be said that colour units suffer more than most, is that any image being continuously displayed, particularly if it is a quad or multiplexed picture, will over a relatively short period ‘burn in’ to the picture tube .... permanently!

In fact it’s quite possible that after a couple of weeks of displaying the same high brightness, high contrast picture, when you eventually switch the monitor off, the after image will remain as a negative reminder of what has been before.

Flat Screen Colour Monitors >>

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