|
When buying any CCTV camera or system it is important to think first about the application the system is being used for and the conditions in which the system will be operating. We hope this buyers guide will help you in selecting a suitable CCTV security camera system.
Wired or Wireless CCTV?
Wireless CCTV
Government regulations now allow licence-exempt systems that can transmit signals up to 100 metres in line of sight. This reduces to approximately 40 metres when used indoors. Simple 1.2 GHz wireless cameras only work on one frequency so you cannot use 2 such products within 100 metres of each other. More advanced 2.4 GHz cameras and receivers are available with 4 selectable channels making multi-camera systems feasible. Even the small covert type of camera can be supplied with its own built-in transmitter.
Remember that CCTV cameras require power to operate. The voltage is usually in the range 9-12V DC and this is typically derived from a small power supply plugged into the mains supply. So wireless does not mean totally wire-free. Battery operation will be measured in hours, so is not suitable for permanent installations. However, it is often easy to pick up the power for the camera in some areas such as the loft of the house. Wireless systems are great where it would be difficult to run the video cable back to a VCR or monitor.
Wireless transmission is also useful for the temporary monitoring of an office or reception area. The miniature wireless cameras with battery power can be fitted to model aircraft or model trains. The receiver can also be connected to a domestic camcorder to record the experience.
Go to wireless spy cameras to see our full range of wireless cameras.
Wired CCTV
Wired cameras guarantee zero interference and can be positioned hundreds of metres away from the monitoring/recording equipment. Often with wired cameras you do not have to power the camera locally. Instead one cable will take both power and video signal back to the recording device.
There are plenty of professional CCTV installers who will give you a site survey and recommend appropriate products but, of course, you pay for this service. Modern technology has now made CCTV products much more affordable and they can be very easy to fit for the average DIY person. This guide will help you choose the correct products and show some simple methods of fitting complete systems to domestic and commercial properties.
Go to wired CCTV cameras to see our full range of wired cameras.
Top of Page
CMOS and CCD Cameras
There are two common types of CCTV cameras, CMOS and CCD (see our Glossary).
The resolution of a camera dictates how sharp the captured image will be and is measured in TV Lines (TVL). CMOS cameras are generally cheaper but do not produce as clear or sharp images as CCD cameras. A typical entry level CMOS camera's resolution is 330 - 400 TVL whereas high resolution CCD camera can provide 400+ TVL of resolution. Since CCD cameras can provide higher pin-point clarity they should generally be specified wherever possible.
Top of Page
Day / Night Infrared Cameras
Choosing the correct camera to operate in the ambient light conditions is possibly the most important specification to understand. Light levels are usually measured in Lux. This is a measure of the light energy arriving on an area 1m2 of surface per second.
Typical light levels are:
Daylight: 10,000 - 50,000 Lux
Shop/Office environment: 500 Lux
Dawn/Dusk: 1 - 10 Lux
Street Lighting: 1 - 30 Lux
Very popular in domestic and small commercial CCTV applications, day / night cameras allow great quality, colour recording during daylight hours. When light levels drop below a certain level the camera's infrared LED's light up allowing the camera to continue recording good quality footage even in complete darkness (0 Lux). The distance the cameras will see at night is dependent on the strength of the LED's.
Go to Day / Night CCTV Cameras to see our full range of day / night infrared cameras.
Top of Page
Recording CCTV Images
Stand Alone DVRs
Digital Video Recorders record images onto a built-in hard drive from one or more cameras. All of our DVRs now come combined with multiplexer functions and programmable motion detection.
Advantages
- all-in-one box for recording, multiplexing, alarms and motion detection.
- no loss of quality when copies taken
- enhanced playback functions, forward and reverse frame by frame playback
- easily connect to networks/internet for remote viewing and playback.
- motion detection recording featuring different sensitivity settings and masking feature. Only movement in the masked rectangle will trigger the output. By resizing and repositioning the rectangles it is possible to allow for pet activity within the observation area.
Go to Stand Alone DVRs to see our full range of DVRs.
PC-based Systems
If you already have a PC then with the addition of a video-capture card and surveillance software you have a powerful digital system. The purchase of a video capture card and software is a very cost effective method of providing a high specification system.
Advantages
- remote viewing over the internet
- software allows many configurations for monitoring e.g. quad display
- time and date stamping with motion detect
- alert wizard, sends email with photo or video clip
- SMS alert / audio alert
- motion detection recording featuring different sensitivity settings and masking feature. Only movement in the masked rectangle will trigger the output. By resizing and repositioning the rectangles it is possible to allow for pet activity within the observation area.
- low-cost all-in-one solution does away with the need for separate motion detect, splitters, quads or multiplexers.
Go to Video Capture Cards to see our full range of PC based CCTV systems.
Domestic VCRs
The simplest low-cost solution is to use a domestic VCR combined with a standard E240 tape, which on long play will give up to 8 hours of recording time.
Advantages - very low cost. Consider purchasing a dedicated VCR for camera recording which can be hidden in the attic or a cupboard making it less likely to stolen by any intruder.
Time-lapse VCRs
Similar to a domestic VCR but with a slower-moving tape that records the camera pictures as snapshots at split second intervals. This can provide up to 960 hours of recording on standard VCR tape.
Advantages - very long recording time, cost-effective. Added features like alarms, auto tape-rewind.
Go to VCRs to see our full range of VCRs.
Top of Page
|
