CCTV System

There are a number of common pit falls that one has to look out for when installing a CCTV system.

Golden Rule
The golden rule is that if you want to be able to make a positive identification of a person or an object it must occupy between 25% & 30% of the monitor screen.

Approximately 80% of all CCTV cameras provide pictures that are so poor a positive identification of an unknown person is just not possible.

Lenses & Power Supplies
As with SLR cameras the picture quality of CCTV cameras is firstly governed by the quality of the optics of the lens. Fitting a low quality lens will negate the performance of the camera.

Cheap power supplies are often a problem as they introduce noise into the picture, that annoying grainy effect.

Most cameras operate at 12V DC or lower. The cheap power supplies provide over 12V DC, this causes the camera circuitry to overheat and results in the noise.

Cable
Here Digital IP CCTV stands head and shoulders above Analogue CCTV.

The problem with analogue camera signals is that as soon as they are relayed down a cable they start to loose picture quality.

The high frequencies which contain the detail attenuate the most rapidly ( √ F1/F2 ).
So it very important to install high double screened quality cable and be aware of the limited distance one can install the camera from the monitoring and recording station.

IP Camera are digital so one does not experience picture degradation due to distance.
The picture quality will be the same if one is viewing the image in the next office or on half way round the world.

Day Night
Besides days/night cameras, one should give consideration to IP thermal imagining cameras they have come down in cost dramatically.

The indirect benefits of using thermal imaging cameras include, no external lighting and the on going operating costs and the ability to locate an intruder in difficult weather conditions.

Cost and performance, especially in CCTV are directly related.

There are many more factors that one should consider, which will gladly discuss with you.

Digital Video Recording Systems
One has a choice of using a DVR using either a Microsoft Windows based operating system or an embedded LINUX operating system.

Experience has taught us that it is advisable to install a DVR with an embedded operating system for the two following reasons:

When the mains power is interrupted the embedded DVR will automatically reboot and continue recording, the Microsoft Windows based DVR normally requires an operator to reboot. With an embedded system the staff and the security personnel can not fiddle with the machine. On the Microsoft Windows based systems we find that all sorts of games and software are loaded onto the system.

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