How Does CCTV Work? The Different Types of CCTV: You Should Know Buying a CCTV Security Surveillance System
How Does CCTV work?
You ought to know this before buying a CCTV security camera system.
If you do, you’ll know what types of CCTV to look out for.
You’ll also be ready with questions you should ask the seller to help you choose the best CCTV surveillance system for your home or business.
A CCTV system involves a significant cash investment.
So, it’s wise to have a basic knowledge of the types of CCTV surveillance systems before you splash your cash on a security camera system.
You must understand that CCTV comes in different shapes and sizes and functionality.
Choosing the right one for your needs could be a tricky affair
Of course, a good professional would gladly assist you with advice, but it doesn’t harm to have a little background, layman’s knowledge on the types of CCTV so that you get your money’s worth and don’t end up shortchanged.
Here are some tips that will help you be better prepared to choose between the different types of CCTV and buy a system for your home or business premises.
Don’t worry if you don’t understand any of the technical jargon mentioned here.
It’s enough you get a broad idea of what is being discussed.
Meanwhile, let’s get down to little basic on security cameras.
What is CCTV? and How Does it Work?
What CCTV means?
CCTV means (Closed-Circuit Television).
They are security cameras that are connected to central recording equipment.
How Does CCTV Work?
The most important component of a CCTV system is the camera.
It’s the ‘eye’ of the whole system.
The camera comprises the lens, sensor and the DSP (Digital Signal Processor) .
The camera lens sends the focused image to a sensor from which the image is passed to the DSP (Digital Signal Processor).
Here’s an important point to remember. A quality lens would be more helpful than fussing over video resolution.
The clarity of images will be determined by lens quality. Based on your needs, don’t compromise on lens quality. Ask the seller what kind of lens will you be getting and will it meet the quality you expect.
The type of lens you choose will determine whether distant objects are visible. Do you want car number plates to be visible or faces to be clearly seen? Then you should pay attention to the type of lens you choose.
As far as possible, opt for a zoom lens. Here you should understand the difference between digital zoom and optical zoom. You’re advised to choose optical zoom. Why is it better than digital zoom?
Digital zoom just enlarges the picture at the center of the frame and cuts off the edges. The lens doesn’t do any work here, only some in-camera processing is done.
Optical zoom on the other hand is just like a zoom that a film camera gives. You get sharper and fuller details of a distant object or view.
Digital Signal Processor (DSP)
The Digital Signal Processor converts the image into a TV signal which is then sent to the central location where it could be viewed on a television monitor or computer screen and recorded to a storage medium.
The transmission of the video signal can be done by a wired connection or a wireless one.
Getting the Right Sensor Type
Two things must be taken into account when choosing the right sensor for the CCTV system. The first is sensor type and the second is sensor size. Generally, CCTV sensors fall into two categories.
CMOS (Complementary Metal-Oxide Semiconductor)
CCD (Charge Coupled Device)
CMOS is cheaper and has a lower power consumption but it doesn’t perform well when it comes to sensitivity to light. Thus the image recorded will lack clarity,If you need clear identification of images, then a CMOS sensor may not be the best bet for you.
CCD consumes power as much as 100 times more than CMOS but it produces clearer images with minimum noise.
If clearer images are what you’re after, then you could do well to go for the CCD option, despite its ‘drawbacks.
Read more about the difference between CCD and CMOS.
Sensor size is also important if image quality is your concern.
Most sensor sizes are either ¼ inch or 1/3 inch. The latter produces double the image clarity of the former. It also inputs more light which when passed to the DSP will result in clearer images.
A larger sensor gives the DSP more data to process and will be useful in producing clearer images in the event a low-end DSP is used.
Types of CCTV Surveillance Security Cameras
Here are the types of CCTV that are commonly available in the market.
This camera is ideal for indoor security and surveillance needs. A big advantage of the dome camera is nobody can quite tell which way the camera is facing at any particular time.
This camera is easily installed and not easily vandalized and comes with an infrared feature.
The bullet camera is a type of CCTV that works well for long-distance viewing. It comes with a protective casing, providing a shield against the elements of nature like heat, dust, and dirt.
They are easily mounted as they come with mounting brackets. You could choose between fixed and varifocal lenses.
- Bullet cameras are suitable for indoor and outdoor use
- Its compact size allows for easily installation
- It offers superior image resolution
The C-Mount camera is future-proof, sort of. It allows for lens change to suit changing surveillance needs.
A standard security camera lens is good for viewing at a length of 40 feet. The C-Mount camera could support a lens that allows viewing beyond that distance.
The C-Mount camera suits indoor security needs well.
Drawback? Its bulky size is eye-catching and doesn’t allow for discreet surveillance.
Day/Night Security Camera
- Can be used both in bright and low-light conditions.
- Captures clear images in dark conditions without the need for infrared facility. Reason? Image sensor is extra sensitive.
- Suitable for outdoor use.
- Available in a wide variety of sizes.
PTZ stands for Pan, Tilt, and Zoom. The camera can be controlled to pan right or left, tilt up or down, and zoom in on a scene.
They are ideal to be used in situations where security personnel man the CCTV surveillance system.
Now that we’ve looked at the different types of CCTV, let’s take a look at the different video formats they support.
CCTV Video Formats
CCTV formats are important because they determine what video resolution you’ll get.
In the early days of CCTV, this used to be the standard format.
With the advancement of CCTV video technology, this format has fallen out of favor.
If you’re looking for video quality in CCTV recordings, then you could do well to stay away from this format.
Resolution: 720×480 Quality: DVD
This promises good quality video recording. It’s the most popular format over the past decade.
The video quality matches that of a DVD. It promises a resolution of about 400% higher than that of CIF.
Resolution : (960×480). Also known as WD1 or Wide D1.
This format gives you the ultimate analog resolution – 34% higher than D1 and 500% higher than CIF.
Advantage: Wider letterboxed video.
WD1 is also compatible with the RG-59 cable used in a previous system.
IP Security Camera System
As the name suggests an IP (Internet Protocol) CCTV system merges video and audio into a single data stream.
This is then transmitted over a network or via the Internet through a Network Video Recorder (NVR).
IP security camera systems are now preferred over analog CCTV systems.
Video resolution is great -720P (1280 x 720) and 1080P(1920 x 1080) – both in progressive high definition video.
Here’s the resolution quality difference you’ll enjoy with an IP CCTV.
For 720p you get a 200 % better resolution than what’s offered by the 960H format.
You get 300% more than the D1 format. As compared to CIF, it’s a whopping 1000% increment.
The 1080p on the other hand offers 200% better quality than 720p.
There’s a 400% improvement in the quality offered by 960H and 600% compared to D1. And compared to CIF, the quality improvement is a staggering 2000%.
It comes with a video resolution of (1920×1080).
If you’re looking for the best high-definition surveillance camera system, this is the format to go for.
What then is the difference between an IP close circuit TV system and the HD-SDI?
The advantage of the HD-SDI format is that it functions as a normal analogy surveillance camera system.
In most instances, you save on installation cost as you could use the RG-59 cable from a previous system. But then you would still have to spend on a DVR if you’re going for a high-end one and the cameras come with steep pricing as well.
But then you would be rewarded with Blu-ray video quality if that’s the kind of video recording you wish.
It comes with 720p and 1080p (1280×720/1920×1080). This format is set to revolutionize the CCTV field.
It offers the best of both worlds- it’s a format that comes with the functionality of HD IP and HD SDI for an attractive price.
One advantage of this format is that long cables, up to 1500 ft long could be used to send and receive video, audio and data.
It’s good to know the variety of CCTV formats available before you go out and buy a system.
If you don’t have the budget or if you just require a basic CCTV setup, opt for a D1 system.
Identifying Your Surveillance Needs: The Key
A common mistake made by most first-time CCTV system buyers is thinking that the more expensive the CCTV system is, the better it would perform. This is not necessarily so.
The key to buying a satisfactory CCTV system is identifying your needs and choosing a system that meets them.
You don’t want to end up paying a whopping sum for a system with features you don’t really need.
So, here are the quick, broad questions to consider before you commit yourself to a CCTV Security Camera System.
Questions to Consider
- Do you need just a basic setup to monitor comings and goings?
- Do you need clear images of faces and objects ?
- Would you prefer a wired or wireless system?
- Would you need an indoor CCTV system or an outdoor System?
- At what time of the day do you expect the CCTV system to serve you best? If it’s to monitor happenings at night, then you would need a camera with night vision capability.
- Would an IP Network Camera (see below) be a better option?
- Would you need a single, double, 8 or 16 camera setup?
- How much is your budget?
Once you’ve identified your needs you’ll be well-prepared to make a buying decision. Also, you’ll need to familiarize yourself with some basic technical terms you should know before you buy a CCTV system or getting an installer to fix one.
Don’t fall for the hype offered by CCTV companies who promote higher-end systems which you don’t actually require.
So far, you’ve learned an overview of choosing a CCTV security camera from which you would have got a general idea of what you have to be prepared for when choosing and installing a surveillance system.
Feel free to explore any aspect you’re curious about by doing some background or asking a CCTV professional