How Security Cameras Work

Security cameras can give anxious homeowners some more peace of mind once they've left their homes.
Security cameras can give anxious homeowners some more peace of mind once they've left their homes.
© ballyscanlon/Getty Images

Do you ever feel a slight pang of anxiety when you leave your house? After locking the door, do you walk away backwards, unwilling to tear your protective gaze away? Instead of reluctantly easing into your car, do you eventually give up, running back to your house to stand guard over your property?

Unfortunately, for those worried about security, it's impossible to be in two places at once. We can't make a trip to the grocery store and expect to know exactly what's going on in every nook and cranny of our homes. We can install locks and alarm systems (which, incidentally, have driven down the number of burglaries over the years), but nothing is failsafe.


If you want to be able to actually see what happens while you're away, security cameras may calm your nerves. Video surveillance allows you to monitor or record activity in and around an area for many different reasons. For example, parents might want to watch over a sleeping child and lessen the risk of a dangerous fall from the crib. But a security camera system around the house can see people who approach the front door and maybe even catch a criminal in the act of breaking in.

­There's a wide variety of security cameras available. Some are large and out in the open, and might serve simply to deter criminals from even approaching a home, while others are tiny and meant to stay hidden from view. If you're considering setting up some type of video surveillance system in or around your home, there are a lot of questions to ask yourself before getting started. To learn about the different types of security cameras out there and which systems are best for certain situations, see the next page.


Types of Security Cameras

The type of security camera system a person installs, like this tiny camera inside an intercom, depends on the kind of activity under surveillance.
The type of security camera system a person installs depends on the kind of activity under surveillance.
© Thomas Jackson/Getty Images

­Before you actually invest in a security camera system, you need to think about what you'll be watching and what you need in order to watch it. The number of cameras you want is probably the first question that should come to mind. Are you focusing on one room in the house, or do you need to keep an eye on several different parts of the house? Will you need to monitor outdoor activity as well as indoor? If you're simply watching over one room, you'll probably need just one camera, but including more areas requires a bigger camera system.

Security cameras are either wired or wireless, and which setup you'll need depends on where you'll want to put the cameras and how visible you want them to be. Wired cameras might be trickier to install, and stray wires can hamper your attempts to be discreet. They do, however, have a typically higher-quality picture than wireless cameras, since their signals aren't travelling through the air.


Wireless cameras have more flexibility, but broadcasts from other devices such as wireless Internet, cordless phones and baby monitors -- can interrupt a wireless camera's signal. Also, keep in mind that if you decide on a wireless system, there's a possibility your video feeds could be intercepted by others. Having someone else monitor your activity around the house or finding out whether or not you're at home defeats the purpose of having security cameras. If you're worried about your personal security, you can check with the manufacturer to see whether or not they encrypt their wireless system.

Larger cameras will be visible, and people typically install them outside or in an area where people know they're under video surveillance. You can also find smaller, hidden cameras online in many different forms -- a tiny camera hidden inside of an alarm clock, for instance, or a small pinhole camera that fits inside of an intercom system.

But before you install any type of security system into your home -- especially the small, "hidden" type -- you should note the legal restrictions on video surveillance. In most states, anyone recording either audio or video in a specified area needs to alert anyone in range of the surveillance device that he or she is being recorded. For instance, if you record someone's telephone conversation without them knowing it, that's illegal. It's also true that if you install a tiny camera into a room in your house without letting anyone know it's there, you're technically breaking the law. If anyone found the camera and wasn't previously aware of its existence, you could potentially face charges.


Installing Security Cameras

Setting up a camera system properly will give you the best surveillance results.
Setting up a camera system properly will give you the best surveillance results.
©Image Source/Getty Images

­After you've determined the area or areas which will undergo surveillance, it's important to set up the security system properly. A poor installation won't get you any results, and if you've never had any experience with electronics, it would be best to have a professional handle the job. Any legitimate security service that offers camera surveillance will probably offer installation, and if they're credible they'll also make sure your system is not only working but legal.

Many camera systems are uncomplicated, so you may be able to install the equipment yourself. Installation procedures will vary according to the model, so it's a good idea to stick to the instructions.


Where you place the camera lens is important. The distance of the camera from its subject should be carefully considered, making sure the right areas are in focus and clearly visible. If you mount a camera to a wall or structure, make sure it's mounted properly so the camera won't shake and distort the picture. Outdoor cameras can deter criminals from ever attempting a break-in, and they can cover large areas, but a camera placed outside should have an appropriate weatherproof casing to protect it from the elements. Tough casings can also prevent tampering or vandalism.

You should also determine whether or not you'll want to record your surveillance. If you're simply making sure your children are safe while playing or monitoring who comes to the front door, a direct video feed with no recorder should be sufficient. But if you wish to see what's happening in a particular area over long periods of time, you should connect a recording system that's compatible with your security cameras. Some people use VCRs to record video, while others run the whole system via a computer and save information digitally. To avoid wasting video, some surveillance systems have motion detectors that only begin recording once the device picks up movement within the area.

As you can see, there are many video surveillance options available. Choosing the right one for your personal needs is a matter of knowing how you want it to work for you.

For lots more information on spy equipment, scan over the links on the next page.


Lots More Information

Related HowStuffWorks Articles

More Great Links

  • Garcia, Anna. "'Spying' made easy." NBC. Dec. 1, 2008. (Dec. 15, 2008)
  • Lowe's Buying Guide. "Select and install a security camera." (Dec. 15, 2008)
  • MES Innovations. "Introduction to the wireless video transmitter." 2005. (Dec. 15, 2008)
  • Video Surveillance. "Video surveillance and security camera information and resources." (Dec. 15, 2008)