Digital security cameras have become one of the most commonly used tools in catching criminals and deterring potential crimes. The cameras keep a constant eye on areas that might otherwise be prime targets for theft, and they’re always on.
Despite their apparent simplicity, there are actually a number of different components used in security cameras to let them do their job. Outside of the basics of a lens, let’s take a look at what makes modern security cameras so useful.
Storage is the basis of any camera system, but digital cameras rely on digital storage. This is superior to film in a number of ways. It has a much longer lifespan, it can be duplicated easily and inexpensively, and the picture quality is generally better. Some cameras rely on solid-state (SSD) storage that’s stored locally, while others can use a LAN or Internet connection to store footage on a network drive or other remote hard drive. This is the preferred method, as it prevents destruction by an intruder.
Night Vision Technology
Although it’s possibly to put together a pretty serviceable camera without it, night vision technology makes any digital security camera that much better. There are a couple universal components that security cameras can use to achieve night vision.
The most important component of a night vision sensor is an infrared (IR) light sensor. IR light is invisible to the human eye, but cameras with IR sensor can use the spectrum to light up the picture being recorded.
An IR cut filter is also important to producing a good night vision setup. An IR cut filter essentially lets the camera know when to ignore the IR spectrum. Without a cut filter, cameras will produced washed out images that are over saturated during the day. Thus, a cut filter lets the camera produce the best picture it’s technically capable of both during the day and at night.
The most advanced cameras have the capability to sense motion and send an alert back to the operator of the camera. This alert can be an audible or visible alert if the camera is being used by a security team, or it can be a text message or phone call for private operators.
There are a few different ways that motion detectors can function. The most common in digital systems is photo-sensitivity. A beam of light is used and focused across a particular part of the area that the camera is being used in. When that beam is broken by an intruder or other object, the change of light is detected and the camera knows to send a trigger. Another common method is to use infrared or photo-analysis. This method looks at changes in the overall image being captured by the camera. It then sends alerts if there is a significant change in what the camera is looking at. The parameters can be adjusted here so that an indoor camera will alert for an intruder, but not for the family dog moving around.
An Internet Connection
For most digital cameras, this is the most obvious need. Using a wired or wireless (Wi-Fi) Internet connection, cameras can be placed online. This allows operators to view the image on the camera remotely, and it also lets the camera send out alerts over the Internet. It also lends a new set of control to the camera – many now have pan, tilt and zoom controls. These let the owner of the camera adjust its field of view remotely, allowing for fewer cameras to be put in place and for better images to be captured.
It’s interesting to see how existing systems work together. Motion detectors, IR light sensors and Internet connectivity aren’t anything new or revolutionary on their own. When brought together, though, they make for one of the most efficient crime-stopping tools that has ever been invented. Digital security cameras are a straightforward idea, but as with all technology, there’s more going on under the hood than meets the eye.