DS Securities Ltd.
47 Oxford Street,
Weston-super-Mare,
Somerset,
BS23 1TN.
Tel: 01934 417730
Fax: 01934 417740

Fire detection and alarm systems, intruder alarms (burglar alarms), security surveillance systems:

Covering:
Weston-super-Mare North Somerset: Bristol Avon: South Wales: South West Areas UK:

Cameras

The cost of CCTV cameras varies widely. This is due to some fundamental differences in the specification which will also affect the choice of camera for a given use.

Monochrome or Colour

Colour cameras are more expensive than monochrome. The gap between the two is, however, narrowing all the time.

While colour pictures are often desirable for security applications some important points should be considered.

Colour cameras have no infra red sensitivity and are much more sensitive in low light conditions. The level of lighting at the scene, therefore, needs to be carefully examined.

Choosing a camera

The right camera choice is dependent upon a number of factors. For example:

A high resolution camera should be considered where greater detail of a scene is required. e.g. Colour 460 horizontal TV Lines, Monochrome 570 horizontal TV Lines.

Selectable Auto Iris (DC/Video) and adjustable mounting (C/CS) are features of a camera that allow a greater choice of lens.

Choosing a more sensitive camera will improve reproduction in poorly lit areas. The sensitivity of a camera is indicated by the minimum amount of light in order for the camera to produce a usable picture.

A pale backdrop is produced by a conventional camera when an object is shot against a bright background. BLC (Back Light Compensation) will counter strong light sources, retaining picture clarity.

DVRs (Digial video recorders)

Essentially this is a device that allows video recording from aCCTV system, without videotape, to a hard drive for storage. The high quality pictures which are date stamped can, if necessary, burned off to a disk which can then be used in evidence.

A DVR CCTV system provides a multitude of advanced functions over VCRs including video searches by event, time, date and camera. Single or multiple video inputs are available. The most common number of inputs are 1, 4, 8, 16.

These are feature rich systems providing:

• Outputs to external video display monitors.
• Connections to external control devices such as keyboards
• A connection to external pan-tilt-zoom drives that position cameras.
• Connections to external storage evices
• Switches and indicators that allow the control of the various features
• Alarm event inputs from external security detection devices.
• Alarm event outputs from internal detection features such as motion detection or loss of video
• Internal CD, DVD, VCR devices e.g.for archiving video.

Covert CCTV

It is sometimes desirable to observe people discreetly. If this is the case, equipment as illustrated can be supplied.
Each of these items (smoke detectors, movement detectors and even a clock) has a tiny hidden camera.
These can be used when a traditional camera is not really an option (i.e. where dishonesty is suspected). These types of surveillance methods can also be employed in places where you don't wish to make the customers uncomfortable by being filmed, for example in a bar or restaurant.