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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.

Time Lapse, VCR's, DVR's, NVR's ...
it's time to go on the record...

Analogue Time Lapse - continued

These recorders have also historically been available as a wide range of different duration models, providing time lapse speed reductions to typically 24 Hour, 168 Hour (7 day) or 960 Hour capability on a single tape; although, 24 Hour and very occassionally 48, or 72 are still the most practical record speeds.

The second variant is actually based on the ‘Long Play’ version of standard VHS, and so is capable of providing near virtual ‘real time’ when used at the 24 hour setting. On playback, the movement is far smoother due to the higher number of recorded images per sec (16.5 pictures per second)., but the down side is the need to use the E-240 cassette, which is loaded with thinner and generally less durable tape stock.

Both types are capable of resolving around 230 - 250 lines in Colour, although some ‘Enhanced’ versions are now able to reproduce up to 350 lines resolution in Black and White.

The thing about VHS recorders, is they’re proven to be robust and reliable over many many millions of hours operation. It is normally considered vital that machines are regularly serviced in line with the manufacturers recommendations, and yet with the continuing drop in unit cost, and the increased longevity of video heads, it is now somewhat difficult to justify possibly spending the equivalent of a basic machines replacement cost, simply to have it go through a full workshop overhaul.

The key to producing good Evidential Quality Video recordings is actually very simple. If the camera is set up correctly with the right lens, and in the right location, good images should be available for the machine to record. To get the best out of the recorder, it is imperative that you use the highest quality (Extra High Grade) branded VHS tapes; or to put it more crudely, cheap tapes nearly always result in crap recordings.

In practice, most very poor quality recordings of a crime, are blamed on either the recorder or the tapes, and yet experience suggests that it is often severe difficiencies in the camera set up, that are far more likely to be responsible.

continued >>

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