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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 ....

Monitor Controls & Functions

Most CRT monitors have only four basic controls on the front panel .... apart of course from the Power switch!

The Brightness and Contrast (and Colour makes five) controls obviously allow precise adjustment of the displayed picture quality.

There are also two common adjustments, which allow the horizontal and vertical hold adjustments to be made, the vertical adjuster being particularly important when using the monitor with a video switcher.

If a unit is changing from one camera to another, it is not unusual to see the second image roll into position, rather than cutting crisply. This roll effect can be minimised by using the 'vertical' adjustment.

As well as the basic front panel controls there are also ... 'Underscan' (to reduce the overall size of the displayed image), a 'Mirror' switch (to reverse the image from left to right), the 'Termination' switch to close off a looping output (used to take an input signal out to another piece of equipment) and the volume control for the internal loudspeaker ....these can usually all be found secreted somewhere around the back of the casing on a
top quality unit.

Some models also allow access to engineering set ups, such as tube focus or black level, but these should most definitely not be fiddled with, unless of course you know what you are doing!.

A very few monitors also have extra equipment built in, such as a quad unit (to allow four pictures to be displayed on the screen at the same time), and line power supplies for dedicated CCTV cameras. The general rule to remember is that the more items that are 'built in' as standard, the more there is to go wrong, and therefore the greater the chances of loosing a key piece of kit, simply as a result of a basic component failure.

Ten 'must know' things about Video Monitors >>

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