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This brief guide will help you understand the basic elements of a typical CCTV system.
It is important that we choose the correct type of camera for each specific installation. Due to specifications of CCTV camera's varying enormously, we select cameras and lenses that offer the best quality picture for your specific environment. We also ensure this is achieved inline with your budget requirements, hence ensuring you get the best picture possible for your money.
Types of CCTV Cameras
These cameras sometimes called body cameras, C cameras or 1/3 cameras (due to the size of the CCD element) are still widely used. They come in many shapes and sizes but generally follow the form of the camera displayed. Many types of lens can be used to complement the camera and many advanced options let the installation technician change the settings to best suit the environment in which they are placed. Outside these cameras are fitted in larger more obvious heated housings.
Many types of Dome cameras now exist, but fundamentally any camera that is encased in a spherical housing is classed as a dome camera. Theses cameras offer the advantage of been virtually maintenance free and importantly hide the angle and position of the camera they contain. Dome cameras are quickly becoming the number one choice for shops, pubs, and schools.
Bullet Cameras tend to have fixed lenses that do not require manual focusing and are manufactured in many styles. Usually waterproof and optimized for exterior use, they are a suitable choice for most domestic properties and some small businesses. Over the past year these types of camera have become more technically able and can now offer a quality alternative to the traditional C camera. Many newer models also come equipped with IR illumination.
PTZ stands for Pan Tilt and Zoom; these cameras and special housings are usually installed where a system will be manned by staff or security guards. They allow the user to control the exact position of the camera along with the focal length via a computer or joystick mechanism. The application of such devices is wide ranging from correctional facilities to schools and shopping centers.
Covert Cameras, in essence, are a means of offering undetected surveillance. Suitable for use in a broad range of applications, these miniature Cameras are hidden in every day commercial and domestic objects. Covert cameras tend to be used where there is a requirement to achieve particular objectives. For example hiding a camera in a stock room will help catch rouge employees. Although it is against the law to have covert systems in place without the proper authorization, we can help with obtaining the required authorization from local courts to install them for use within a set time frame.
Cameras with higher resolutions will produce a better picture. A common measure of resolution is TVL (number of TV lines the camera generates), i.e. a camera with a 300 TVL image is generally not as effective as a camera with a 480 TVL image. Most cameras over 400 TVL will offer an excellent picture. The overall quality of picture is dependent on the type of camera lens, wiring, monitor and recording system.
Infra Red Lighting Cameras
The range that your camera will see in the dark will depend on the sensitivity of the camera, the ambient light and lens combination. Where additional lighting is unsuitable infra red provides the best solution. The human eye cannot see infra-red light, however most monochrome CCTV cameras can. As such the invisible light can be used to illuminate a scene; this allows night time surveillance without the need for additional artificial lighting. Infra-red lamps cannot work with colour cameras; therefore the best alternative is to use a dual technology camera (colour by day, monochrome at night) together with IR lamps. These cameras are called Day/Night cameras and we install these as standard in the majority of installations.
Recording and Viewing your Image
Recording the image is one of the most important parts of the system, and this can be done in one of two ways, digitally via a DVR or if price is an important factor, then by the traditional video method. Although over the past few years digital recording solutions offer real advantages over time lapse Videos. Not only are the recorded images superb but they offer many functions and facilities that Time lapse video recorders simply don't provide. We predominantly install DVR based systems as we can now offer entry level DVR technology at similar prices to outdated VCR's. Using Time Lapse videos is still the most cost effective method if your requirement is for a single camera system. The screen that you use to monitor your pictures is another important factor, we offer monitors that range in size from 5" to 42" plasma screens. Many customers are now choosing TFT screens; these are particularly beneficial where space is a premium.
Digital Video Recorders (DVR)
DVR's are excellent at reproducing high quality images with little noise or picture degradation and are extremely useful in calling up an event or moment in time. Fundamentally DVR's allow you to record several images at once; this information is stored digitally on a Hard Disk rather than a tape. There are many advantages over VCR's, VCR tapes begin to wear and deteriorate from the moment they begin recording while Hard Disk recording remains at the same high standard throughout its working life. In addition to the obvious quality benefits, DVR's offer a number of additional features not available with Multiplexers and VCR's. Certain DVR's make it possible to view and control your CCTV system from computers around the world.
Quality of Installation
An often over looked area, but system installation can have a huge impact on performance. It is important to understand video transmission in order to select the most appropriate installation method. Using the wrong cables, poor camera positioning, bad connections will affect the overall picture quality. Our fully qualified engineers understand video transmission and posses many years worth of experience to ensure each of customers receive the best installation possible.