Introduction to Security Camera Systems

In essence, a security camera system consists of a number of security cameras, a digital video recorder to record the cameras, and wiring and connectors to connect them all.You may want to check out Security service for more.

Security cameras come in a variety of different styles:

  • Cylinder-shaped bullet cameras with built-in lens are weatherproof and ideal for outdoor applications
  • Dome cameras with a dome shape and an integrated lens are usually used indoors, although some are fitted with a ‘armor housing’ that allows them to be used outdoors.
  • C-mount or ‘box’ cameras, with a rectangular shape and a lens selected and mounted separately, are only used indoors for outdoor use, unless they are housed in separate housings. Such cameras are commonly used in commercial environments
  • Hidden cameras can come in a variety of sizes, including super-small ‘shadow’ style cameras that can easily be concealed, or concealed cameras built to look like something else, such as a teddy bear, a smoke detector, or a sprinkler head. Typically these cameras are equipped for indoor use only, and have an integrated lens.
  • Pan-Tilt-Zoom (PTZ) cameras allow remote operators to pan (back and back), tilt (up and down) and zoom the lens in and out. Typically they are huge, and can be used inside or outside.

Your option for each camera in your system will depend on whether you want to install it indoors or outdoors, the size lens you need, the resolution (the higher the resolution, the clearer the image), whether you need infrarot for nighttime viewing, and the type of mount (do you need to mount it on a wall , ceiling, pole, etc.) and, of course, the budget.

A 3.6 mm lens gives the widest viewing angle you can get on a camera without distorting the image. That will offer about 30 feet of facial detail. You would need a higher millimeter lens if you need facial detail farther than 30 feet from the camera. A higher millimeter lens gives you more focal distance thus decreases viewing angle. There are varifocal lenses (for example, 5 to 100 mm) which allow variation of the camera’s focal distance. That’s useful when you don’t know exactly what lens you’ll need up front.

You do want to choose which type of Digital Video Recorder (DVR) to record the cameras you need. Some DVRs come in variants of 4, 8, or 16 camera inputs (aka ‘channels’), but there are DVR models that can record as many as 64 cameras. Keep in mind that adding camera inputs to an existing DVR later on is usually not feasible so you’ll want to ensure future growth. Look for a DVR with 30 frames per second (fps) per camera in ‘real-time’ recording mode. The compression system they are using also differs from DVRs. The best compression technology compresses the video data so that it can be stored on the hard drive in as little space as possible, and loses the least amount of information (image quality) in the process. Oldest (worst) to newest (best) encoding technologies are: J-PEG, M-JPEG (aka MPEG), MPEG4, and H.264. Next, decide how much room you’ll need for hard drive. The DVR will start recording over the oldest video on the device when all of the hard drive space is used up. Most people chose to keep the stored video on hard drive for 2 to 4 weeks. Certain features you need to look for in a DVR include remote viewing and service, audio support, and ease of use and backup for events.

Finally, all the cabling and connectors are required to power the cameras and the DVR, and to link the video signal from the cameras to the DVR. There are two basic approaches to wiring your system: using plug-and-play cables which have the connectors pre-attached vs. using RG59 cable which is shielded more heavily (so less problems with interference) but requires that you apply the connectors yourself. This is better to use plug and play cable, but it would only be effective if the cable runs are less than 100 feet, and no florescent lighting is used in the building in which it is housed, and no high-powered infrared cameras are used. Your protection dealer will help you decide whether all of the connections and parts you need are in stock.

Other items to consider when designing your camera system are power and surge protection, a lock box to secure the DVR and a monitor to view the cameras directly from the DVR (as opposed to over the network).

Once all of the components are powered, the cameras are connected to the DVR and a monitor is plugged in, you should be able to view your cameras immediately. The program on the DVR lets you configure your configuration for features such as network monitoring and motion detection.

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