Closed-circuit television (CCTV) is the cornerstone of your home or business security. We will discuss how CCTV cameras work and explain their function and security benefits around these products in further detail.
- What is a CCTV camera?
- How does a CCTV camera work?
- How cameras connect up to a surveillance system
- Styles and features of various CCTV cameras
- How camera systems are usually set up
- The importance of using multiple cameras
- When do you need a CCTV camera?
- Smart cameras and home security systems
CCTV or Closed-circuit television is a video surveillance system that works by recording or displaying footage from one or more cameras and transmitting the footage to one or more monitors. The owner can view video feeds in real-time or as it’s being recorded.
To understand this answer in more detail, I have written this article to explain how these systems work.
In earlier years, when CRT monitors were around, CCTVs were being used for security to keep an eye on employers, people who weren’t authorized to be on private property, or keep public areas safer.
Although there are a wide variety of CCTV cameras, I have put together some information to cover as many different types as possible to paint a complete picture I can.
What is a CCTV camera?
A CCTV camera is specifically designed for surveillance that can record video (and sometimes audio) with enough lens angle to maintain enough visual clarity while maintaining a wide enough viewing angle within today’s current technology limitations.
These kinds of cameras are usually built to be vandal proof although certain types of CCTV cameras are vulnerable to physical damage.
These are usually the cheaper variety or ones used more for home use. They are often a camera concealed inside an acrylic dome.
A CCTV camera is commonly equipped with IR lighting, so it has plenty of light to record at night while not visible to the naked eye.
How does a CCTV camera work?
A CCTV camera works like most cameras, taking reflected light from objects and focusing it through a lens that focuses the light onto an internal image sensor.
There are a few different types of image sensors. But CCD and CMOS image sensors are most commonly used for CCTV cameras.
The image sensor data is processed further with internal electronics within the camera and sent out as wireless or network data. This is where CCT cameras start to work a little differently.
Most CCTV cameras work off motion. This saves storage space for recorded footage, as the camera will only start recording once any movement is detected.
This sometimes has an unfortunate disadvantage when a camera is installed and directed toward a tree on a windy day, for example.
How cameras connect up to a surveillance system
We will cover the two main connectivity types, wired and wireless, a little further in this article.
Let’s focus on how these cameras integrate into surveillance systems. In most cases, cameras are connected directly to a centralized DVR or NVR.
These units are usually located inside some control room with increased security to gain access.
The recording devices store the camera footage in a local storage unit which can be accessed remotely for both the stored footage and the real-time feed.
Cloud storage is another way these systems can store recordings and offer additional benefits.
Some of these include securing the recordings straight after the cameras have begun recording to data centers or servers with plenty of redundant backups to ensure your information never gets lost.
Styles and features of various CCTV cameras
There are many differences between the makes and models of CCTV cameras. Here are some features that are offered by multiple cameras.
How does CCTV Storage work?
Some models of camera offer recording directly to an onboard SD card. This removes the need to connect the camera to anything and allows it to function independently.
Most of these kinds of CCTV cameras offer one or more connectivity options in addition to storing the recorded footage directly on an SD card.
Here is a comparison of the two connectivity options regarding CCTV cameras.
Some CCTV cameras offer a wired-only connection to the DVR or NVR. This is usually done using CAT cable used in networking.
Of course, CCTV cameras come in wired and wireless, but let’s look at wired connections first.
CAT cable is an excellent way to transfer data over a wired connection, as this is what this type of cable was designed to do.
The shielding and solid core cable strands allow for excellent bandwidth and interference reduction.
Most security camera installers will have ethernet or CAT cable rolls on hand and crimp on the connectors at both ends after the cable has been correctly installed.
The wired connection is the most reliable and can maintain good connectivity over longer distances.
Wired cameras will be able to deliver a more consistent and quality image compared with wireless cameras.
Wireless security cameras
One noticeable beneficial feature of wireless CCTV cameras is the ease of installation. You don’t need to run cables long distances to get them working.
However, you will need to perform a signal quality test before installing a wireless-style camera.
It may be easiest to purchase one to test first. Then, if it doesn’t work out, you could keep it for the closest camera to the control room if at all possible if returning it isn’t an option.
Another way to test the signal is to set up a wireless router in the control room and take a laptop to the location where you need your camera.
Check the signal quality to establish a baseline for whether a wireless camera would work.
Considering that many factors contribute to diminished signal quality and strength, a practical test is always a sensible choice.
It only takes a wall with metal inside between the central location and your camera to ruin the signal making it a no go.
So, there are no guarantees that things will work reliably with a wireless connection, so it’s always a gamble in this situation.
There are a few different mounting choices for CCTV cameras regarding brackets and camera design.
There are mounting variants for each of the following, but here are some examples:
- Wall mount. (I shape, L shape).
- Ceiling mount. (I shape, U shape).
- Pole mount. (All various proprietary designs).
- Universal brackets. (Swivel, three-dimensional adjustable joint).
- Box or junction mounting. (Round, square).
In addition to this, CCTV cameras come in body mount options for various applications like the police, to name one example.
How does the lighting for a camera work?
More often than not, CCTV cameras have an array of Infrared LEDs built around or somewhere on the camera. These Infrared LED arrays illuminate the camera’s area of view.
This is excellent for poorly lit areas at night where you don’t have an outside floodlight or lights turned on inside a building.
As we can’t see this type of light with our eyes, it allows clear vision filming in the darkest conditions where people can’t see, given the poor lighting conditions.
There are different styles of cameras depending on their function. Here are some examples:
- Bullet-style cameras.
- C-mount cameras.
- Dome-style cameras.
Like any camera, you get various image resolutions, usually reflected in the price tag. HD cameras range anywhere from 720p to 1080p or better.
Some older non-HD cameras wouldn’t be desirable as you would see much when reviewing footage for any given situation.
So it goes without saying that anyone would want the best resolution possible when choosing a camera. The best resolution is suited for the budget, that is.
Does a CCTV camera record sound?
Yes, some CCTV cameras can record sound using built-in microphones, but not all cameras have this capability. Legal considerations vary, so it’s important to understand local regulations regarding audio recording.
Not all CCTV cameras can deliver audio with the feed. Some models don’t have this feature, and it’s essential to check to see if the one you are looking to buy has sound capabilities if it’s something you need.
I would recommend getting CCTV cameras with audio. It’s better to have it and not need it but have it when you need it. You simply never know.
The internal components required for a CCTV camera to record sound
The internal components required for a CCTV camera to record audio include a microphone, an amplifier, and an analog-to-digital converter (ADC).
The microphone captures the sound waves in its environment. These sound waves are then amplified by the amplifier, which increases the signal strength so that it can be effectively recorded.
Finally, the ADC converts the analog audio signal to a digital signal that can be stored and processed by the camera’s recording system.
In addition to these components, many modern CCTV cameras contain noise reduction algorithms and filters to reduce background noise levels during recordings.
These algorithms help refine the captured audio signals and remove unnecessary or unwanted noise. This ensures that only relevant sound is recorded with greater accuracy and clarity.
Finally, most commercial CCTV systems also feature encryption technologies that allow users to store their audio recordings securely. This protects against any potential illegal access or misuse of sensitive audio data.
Some CCTV cameras are powered with the CAT or ethernet cable. This makes the wired option more attractive as you only have to be concerned with one cable.
Wireless cameras can have a power adapter or power brick plugged into an outlet to function.
While other wireless cameras can operate off batteries, it goes without saying that this option has a significant drawback. Therefore, you had best set up a schedule for replacing batteries to keep it going.
Another type would be solar power in conjunction with a rechargeable internal battery. It charges the battery throughout the day and relies solely on it at night.
Solar-powered cameras for wireless connectivity is the preferred choice, as you won’t need to replace the battery as often. You will only need to replace the battery after it has gone through its expected lifespan of cycles of draining and charging.
Please read further to learn more about CCTV cameras and power options and if they require electricity.
Some CCTV cameras have motorized motion capabilities that allow cameras to be rotated to specific areas of choice by automatic or manual control, which can also be done remotely.
This allows cameras to pan left and right, up and down. In addition, it dramatically opens the surveillance area for cameras.
This feature is often present on cameras with zoom capabilities to make observations in specific places of better quality.
These cameras are commonly called PTZ (Pan Tilt and Zoom).
There are two main types of zoom technologies used in this feature.
- Optical zoom. This relies on the manipulation of the lenses themselves.
- Digital zoom. This is simply a software-based solution that zooms into the prerendered image itself.
There is no question that optical zoom is superior. Having the lenses so the work of bringing something closer into view will deliver higher quality and less pixelated image.
You can think about digital zoom as viewing an image on a computer or phone and zooming into it. As you zoom further into the image, you will notice how the quality quickly drops, leaving you with a grainy and sometimes unviewable image.
When lenses are used to zoom, the light is concentrated further into a specific area by using the lens to make a form of magnification.
As you are doing this before the image sensor processes the image, you get a better-quality result.
How the outdoor elements affect cameras
Two main types of cameras are found on the market today regarding the chosen construction and materials. Ones made for indoors and others that are made for outdoor use.
It will be a bad idea to use an indoor camera outside. It will rust and corrode in no time, leaving you with something that must be thrown away.
Outdoor cameras are designed to withstand the various elements that the outdoors subject upon them.
Sunlight over time and water are the two primary concerns. The sun causes plastics to go brittle, and water can cause metal corrosion or rust.
So, outdoor cameras are designed with special seals to stop water from entering anywhere internally inside the camera.
Quite often, installers must be careful when installing cameras outside. Directions must be followed as per the manufacturer to ensure that the product remains waterproof after cables are installed and the camera is finally mounted.
How camera systems are usually set up
The camera is more desirably mounted on a wall or ceiling high enough that potential vandals have difficulty gaining physical access to or noticing them.
Cameras are usually placed in multiple locations to provide some overlap of all the possible areas that need to be monitored.
The importance of using multiple cameras
It is seldom the case that one CCTV camera is enough. In most situations, a network of carefully placed CCTV cameras ensures less chance of dead zones.
This means that if someone knows the camera viewing locations, they can conduct whatever bad business they wish where cameras cannot view them.
This can harm surveillance efforts and render an entire CCTV system useless.
So it’s vital that careful planning and testing are carried out to ensure the camera system covers every angle.
When do you need a CCTV camera?
Whenever you feel that monitoring a specific location with video or audio surveillance could solve a problem, this is the time to consider a CCTV camera.
The possible list of needs is so extensive that I wouldn’t even try to list most of them.
But be aware that a camera is at a convenient price point for most situations. You won’t always need an expensive camera for specific needs.
Some uses can be anything from home security to ensuring a large business property remains carefully surveilled to persecute unwanted wrongdoers.
Smart cameras and home security systems
Smart CCTV cameras and surveillance systems are evolving to become equipped with what most people call smart technology.
They can now detect in more detail, identify behaviors, and employ facial recognition and smartphone interaction.
While some feel this is becoming a problem and is gradually taking away our privacy rights, others feel these features help provide an extra layer of security.
Another advantage is, recording directly to the cloud is a great way to prevent potential perpetrators from grabbing your storage unit to get rid of the evidence.
All the recorded videos or images are stored on cloud storage to make data retention safer and more robust.
CCTV Cameras are sophisticated devices that are becoming more and more affordable as time goes on.
Gone are the days when surveillance technologies were only available to people with deep pockets. More features are available with even the cheaper cameras making them a potential solution for many more usage cases.
Smart doorbells are an example of a scaled-down version of these cameras and offer excellent security features for your front door area.
So now that you know a little more about how they work, you can make better decisions when purchasing or considering CCTV cameras.