The trends are using color system these days. The color cameras make clearer identification than B/W ones. But, in a low light condition like in 0.1 lux, you may need B/W cameras because they generally require lower illumination.

What parts do I need basically?

Camera body, lens, mounting bracket, cable, AC Adapter are the basic parts to produce video and many of recently developed economic mini camera packages come with all of them (but you should check carefully if they really do or not). You may add CCTV monitor (if you don't use your own TV), quad splitter or switcher to combine more than one camera (you might want to consider an observation system which includes all the parts mentioned above), Time Lapse VCR, outdoor housing case and other accessories. Or, you may choose wireless systems to avoid cabling. Network based Web Camera Servers are popular these days for remote surveillance on the Internet and for convenience in LAN or WAN system.

If you need 4, you have many choices in the market. You can use quad splitter or 4 channel switcher to combine up to 4 cameras into one monitor or TV. Or, many "observation systems" come with all in one package, including quad or switcher built-in monitor and 4 cameras. If you need only 2 or 3 cameras, switching system would be all right. If you need one camera, try to use standard TV rather than special monitor so that you can save a lot. You may need an 8 channel switcher or multiplexer to see more than four cameras on one monitor.

Do I need hidden camera?

You can build one with mini or ultra-mini camera. Some ultra-mini cameras are only a quarter size so that you can easily hide. Hidden camera built-in clocks, radios or smoke detectors are also available but they are generally quite expensive. One thing you should remember is that, in most US states, hidden cameras with audio are prohibited.

Do I need outdoor camera?

You may use outdoor housing case, with or without heater and/or blower. The heater and/or blower built-in housing cases generally require separate power supply. Some cameras are made water resistant and don't need separate housing cases. Some of them also have removable sunvisor covers. Hi-tech cameras like web camera servers, which have built-in computer system, are not recommended for outdoor unless properly protected by heater and/or blower built-in housing case.

Economically commercialized infrared cameras, some of them are also water-resistant to be installed outdoor, can see up to 30ft distance in total darkness. If you need to see farther, you may need professional infrared illuminators but they are usually expensive and complicated to install due to its emission of heat. Infrared cameras work as ordinary video camera during daytime. Most color infrared cameras work as B/W ones at night. Minimum illumination for most B/W cameras is 0.1 lux so you do not necessarily need infrared cameras or illuminators if there is some kind of lighting.

What angle of view do I need for the lens?

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 a little distorted pictures.

A manual zoom lens of, for example, 3.5 ~ 8.0mm is what you manually adjust angle of view from 3.5mm to 8.0mm. 3.5mm means about 90o of diagonal view angle on 1/3 " sensor camera and 8.0mm sees about 38o. Auto zoom lens can be adjusted at the control center or from your computer.

A little of auto iris functions are built-in in most of cameras included in the observation system. But, when you use professional cameras you may need separate DC drive auto iris, a motorized device to meet the changes of lighting condition of the sun. Generally, auto iris device is not necessary for indoor application with artificial lightings.

A pinhole lens with a tiny opening can be hidden easily in a wall or ceiling or other objects. Many recently and economically commercialized mini cameras have built-in pinhole lens . A pinhole lens for professional camera is very professional and expensive.

If you use 1 camera, TV (which has RCA video input) is definitely recommended. Even for more than 1 camera, if you use combiner like quad splitter or switcher, TV would be fine. But, for special features like slave video output(to be connected to additional monitor), alarm systems or for packaged observation system, you may need professional CCTV monitors.

Unless it is necessary to see four pictures at the same time on quad split screen, switching system which shows the pictures one by one(you can control dwelling time) is recommended for its larger images.(Quad splitter generally has the switching function also, so if you're willing to spend more money, a quad monitor would be more convenient).

12" was the major size during past years but these days, 14" for color and 17" for B/W became very popular. Or, 4" LCD monitor to place on the desk is another choice.

Wireless system is convenient to avoid cabling works, but is limitedly affected by high voltage power lines nearby, unseen razor waves, huge machines like lathe, metal walls and others. Some wireless system goes up to 300ft and others up to 700ft.(It varies depending on the booster inside the transmitter and you can not change it without permission from FCC.) Coaxial cable is conventional in this field and proper for professional cameras. It goes up to 450ft without losing the picture quality. Multiple wires like DIN carries not only video but also audio and power. It can be extended up to 250ft. For remote surveillance, you should consider web cameras.

For professional cameras, the power source is better located close to the camera. You may use 12VDC AC adapter if the camera is installed indoor and if the power outlet is within 5ft. If the professional camera is installed outdoor or the power outlet is located far, you should use 24VAC AC Adapter. For DIN cables, which come with the observation system or mini camera package, the power source can be close to the monitoring site, but the distance from the power source to the camera should be less than 250ft.

Many CCD video cameras work with 12VDC and if you can connect correct polarity, you can use a battery pack which produce 12VDC. Some wireless cameras have a battery compartment. Or, if you want use it in a car, you may use a "power cord" (easily found at any auto parts shop) which can draw 12VDC through the car cigarette lighter . Again, you should match the polarity.

When you need to send the video image more than 250ft on mini DIN or RCA cable, or 450ft on coaxial cable, you need to use video amplifier. But system cables like large DIN cables cannot be connected to video amplifier because amplifiers usually have RCA in and out connectors. You can also use video amplifier when you want to connect one camera to 2 monitors.

Many observation systems, which come with full package of professional monitor and multiple cameras with DIN cables, have built-in time & date generator. But, most mini cameras don't have them and you need one if you want the time & date shown on the monitor. It is to be connected between the camera and the monitor with RCA in and out jacks. Time Lapse VCR usually has built-in time/date generator.

Do I need motion detection? And, alarms?

Better, let professional installers do the work for motion detection and alarm because, in many cases, the motion sensors are trouble makers. But, in digital video recording system, where the motion detectable area can be assigned over the computer monitor, motion detection is simple and easy.

Do I need Pan, Tilt and/or Zoom control?

A lot of investment and professional installers will be requested. But, Speed Dome that already has built-in PTZ is much easier to install, maintain and control. (You can control it with mouse from your computer.)

Conventional Time Lapse VCR, even though inconvenient to review the recorded pictures, is surely economical than DVR(Digital Video Recorder). DVR is getting more and more popular for its convenience and picture quality. (Standard home VCRs are not good to run 24 hours a day and some are only for play, not being able to record.)

Do I need computer based observation system?

With a video capture card which converts analog signals to digital ones, you can connect any CCTV video camera to the computer if it has enough capacity to handle the video files. Way that is more professional is to use web cameras that run fast over the Internet or Intranet(LAN or WAN) with small file sizes. Many so-called "PC camera" uses C-MOS chip instead of CCD chip and also requires separate software.

Most of the computer based systems have access control.

To see it on the Internet, you need network line like DSL or T-1 and IP address which is to be assigned to the camera. To see it over the Intranet like LAN or WAN, you just add the web camera server to LAN or WAN as a computer.