B/W or Color?
Color Cameras are more popular, due to their clearer identifications. But, in low light conditions, B/W cameras are more ideal, because they generally require less illumination. Newer models of Day/Night cameras work as color camera during daytime and B/W at night.
What basic equipment is necessary for video surveillance?
- Camera body
- Cable, and
- Power Supply
Some cameras (like dome and bullet type cameras) come with built-in lenses. You will also need CCTV monitor (or regular TV), quad splitter or switcher to combine more than one camera, recorder (like DVR), outdoor housing case and other accessories. Wireless systems are great way to avoid cabling. Network based Web Cameras and DVRs are for remote surveillance.
What if I need more than one camera?
A quad splitter, 4 channel or 8 channel switcher, or multiplexer can be used to combine multiple cameras into one monitor or recorder. DVRs usually come with a built-in multiplexer.
If you want a hidden camera, you have two options; you can either build one with a mini or an ultra-mini camera, or buy one. Some ultra-mini cameras are only as big as a quarter to hide more easily. Hidden cameras built-in clocks, radios, or smoke detectors are also available but are generally more costly. Please note that, in most US states, using hidden cameras with audio in a covert way is prohibited.
Placing cameras outdoors
You may use an outdoor housing case, with or without heater and/or blower. The heater and/or blower built-in housing cases generally require a separate power source. Some cameras are made water resistant and do not need separate housing cases. Some of these also come with removable sunshields.
When are infrared cameras necessary?
Economically commercialized infrared cameras, some also water-resistant to be installed outdoor, can see up to 40 to 80ft distance in total darkness. You may also use infrared illuminators, which can illuminate up to 100ft (Color cameras, unless their IR filter is removed, do not work with infrared illuminators.) Infrared cameras work as ordinary video camera during daytime. Color infrared cameras work as B/W ones at night.
What is an ideal angle for a lens to cover?
Widely used and recommended angle of view of the lens for surveillance purpose is 72o to 78o. Narrower will give you clearer pictures. Wide angles like 92o can cover more area but it may show distorted pictures.
Vari-focal vs. Zoom Lens
Focal length and focusing for vari-focal lens should be adjusted respectively while zoom lens focus automatically when the focal length is adjusted. Manual zoom lens needs to be manually adjusted while motorized zoom lens can be controlled with a remote controller.
Manual Iris vs. Auto Iris
If the lighting condition changes significantly and frequently, like the sun, an auto iris lens is required. If the lighting remains same, a manual iris or a fixed iris lens is recommended. Most CCTV cameras accept DC auto iris lens while some special cameras use video auto iris lens.
Do I need pinhole lens?
A pinhole lens with a tiny opening can be hidden in the wall, ceiling or other objects. Some mini cameras have a built-in pinhole lens. To mount a pinhole lens to a standard camera is very expensive.
CCTV Monitor vs. Standard TV
If you are use only one camera, a TV (which has a RCA video input) is definitely recommended. Even for more than 1 camera, if you use a processor like a quad splitter, a switcher, or a DVR(Digital Video Recorder), a TV would be fine. But, for special features like slave video outputs (to be connected to additional monitors), alarm systems, or for multiple inputs, professional CCTV monitors work best.
CRT vs. LCD Monitor
Conventional CRT monitors are bulky and heavy while they are cheaper than LCD monitors which has higher resolution. If you have enough budget and want to use one monitor for both CCTV and computer, LCD monitor is recommended. 17" & 19" are popular sizes for LCD monitors.
Monitor Input Connectors
BNC is commonly used for connecting to both CRT and LCD monitors. These days, most LCD monitors have an S-Video input as well as a 15-pin Mini D-Sub for PC Signal input.
Wireless vs. Wired Transmission
A wireless system is convenient in avoid cabling works, but can sometimes be affected by high voltage power lines, unseen razor waves, large machines like lathes, and metal walls. Wired transmission guarantees stable video. Coaxial cable is most used for CCTV cameras.
12VDC vs. 24VAC
24VAC system is more professional and most CCTV cameras work with a 24VAC power supply. Mini cameras, dome cameras, and bullet type cameras are usually 12VDC system. Recently developed cameras have both 12VDC and 24VAC inputs.
Battery operated cameras
Many small sized cameras work with 12VDC battery pack; however it requires correctly matched polarity. You may also use a "power cord" (easily found at any auto parts shop) that can draw 12VDC through the car cigarette lighter.
Most DVRs now come with a built-in motion detection software to trigger recording. You can program the sensitivity and detection zone. It works with any change of the pixels within the picture frame. You can also install a hardware motion detector connected to the DVRs to trigger recording.
Pan, Tilt, and Zoom control
A dome type camera that already has built-in PTZ is easy to install, maintain, and control. You can also control it on the computer monitor with the mouse if the PTZ system is connected on the network via a video server.
Time Lapse VCR vs. DVR(Digital Video Recorder
Conventional Time Lapse VCR, despite the inconvenience in reviewing the recorded pictures, is more economical than a DVR(Digital Video Recorder). DVRs are more popular for its convenience and picture quality.
Remote Surveillance over the Network
Network DVR or Web Camera, connected to the Internet or LAN and assigned with an IP address, can be monitored at a remote place. DSL or T-1 line is required to be connected to the Internet.
HD CCTV System
As the TV Broadcasting changed to HD (High Definition) System, it's time for HD cameras to come to the market. Still, the traditional standard resolution system does not accept HD cameras and you have to prepare peripheral devices such as recorders to accept the HD cameras.