Video Surveillance Equipment (Introduction)

Ahmer A Hamid
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INTRODUCTION TO VIDEO
SURVEILLANCE EQUIPMENT
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INTRODUCTION TO VIDEO SURVEILLANCE EQUIPMENT AHMER A HAMID
Contents
Introduction:.................................................................................................................................................2
Wireless CCTV systems.............................................................................................................................2
Wired CCTV Systems ................................................................................................................................3
Types of CCTV Systems: ...............................................................................................................................3
Analogue Cameras: ..................................................................................................................................3
IP Camera:.................................................................................................................................................4
Types of IP Cameras: ................................................................................................................................4
Decentralized vs. Centralized IP Cameras: ..........................................................................................4
Fixed vs. PTZ IP Cameras:.....................................................................................................................5
Components of an IP Camera: .....................................................................................................................5
Lighting Controllers:.................................................................................................................................5
Lens:..........................................................................................................................................................7
Housing:....................................................................................................................................................7
Sensor: ......................................................................................................................................................8
Video Compression: .................................................................................................................................8
Indoor/Outdoor Camera:.............................................................................................................................9
Recording Devices: .......................................................................................................................................9
Networking:................................................................................................................................................11

Introduction:
As the name implies, Closed Circuit Television (CCTV) is a system in which the circuit is closed and
all the elements are directly connected. This is unlike broadcast television where any receiver
that is correctly tuned can pick up the signal from the airwaves. Directly connected in this context
includes systems linked by microwave, infrared beams, etc.
The most basic CCTV system will consist of cameras and a just a television monitor; but most
nowadays will also include a recording device, most typically a digital recorder - these devices
now quickly replacing less flexible video recorders. There are three basic functions of CCTV
systems:
 Deterrence
 Detection/response
 Provision of evidence
Closed Circuit Television (CCTV) systems are broadly divided into two known types, namely: wired
CCTV systems and wireless CCTV systems
Wireless CCTV systems
Wireless CCTV systems are increasingly becoming a popular choice among CCTV buyers on
account of the ease of installing such a system, lack of cabling requirements and assured mobility.
The key advantages are:
 A wireless camera can be moved to other locations requiring observation while it is
difficult to move a wired camera.
 Best suited for locations requiring temporary observation or in a temporary location.
 Wireless camera can be hidden to detect theft or pilferage
 Wireless systems are cost effective, re-deployable and portable.
Disadvantages of wireless CCTV systems:
 Wireless systems require a dedicated frequency to transmit signals from the camera to
the receiving and recording station.
 Frequencies may be subject to various interruptions by use of electric motored products,
air conditioning, fluorescent lighting or cordless telephones which affect the picture
quality.
 Wireless camera may not provide the best picture quality as such systems are susceptible
to picture distortion while wired cameras provide relatively better picture quality.
 Wireless CCTV cameras may need electric power which implies a wire runs through the
camera though the video connection is wireless.
 Wireless systems require wireless technology-specific expertise to diagnose and fix break
downs in the system.

Wired CCTV Systems
Wired CCTV systems connect the camera to the recording device and monitor with the help of
standard coaxial cables or Unshielded Twisted Pair (UTP) cables or fiber optic cables.
The key advantages of wired CCTV systems are:
 Provides the best picture quality with zero interference
 The camera can be located hundreds of meters away from the recording or monitoring
equipment.
 All sensors can be run from a single power supply
Disadvantages are:
 Cabling and installing can be costly and tedious task, requiring help from experts
 Observation is fixed to a specific area and the camera cannot be easily moved to another
location.
Types of CCTV Systems:
Analogue Cameras:
Simplicity – Analog video has been a universal standard for several decades. Virtually any analog
CCTV camera can be plugged into any DVR, regardless of brand. So CCTV literally is as simple as
plugging a cable into the camera and into a DVR. Simply point the camera; plug in the cable;
power on the DVR. There are many significant limitations to CCTV, but from an installation and
learning curve standpoint, CCTV is simple.
Price – In virtually all cases, IP cameras are more expensive than analog CCTV cameras. However,
once customers learn of CCTV's inherent limitations and the advantages of IP, many often
discover that IP actually costs less than analog. Let's explore.
These systems do have limitations in terms of Scalability and Installation Flexibility – CCTV stands
for closed circuit television, and that is its first weakness. It's closed, which means it's hard-wired
and difficult to scale. It's an "octopus" installation (with each camera's cable being an "octopus
leg" extending out from the DVR, the "octopus head").CCTV DVRs have a fixed number of camera
inputs, and on most DVRs, there's no way to scale beyond this limit. For example, if a DVR has
eight inputs, you can record up to eight cameras. When it's time to add a ninth camera, your
options are to replace the entire DVR with one with a higher port count or add a second
independent DVR. Some more limitations are discussed under:
Resolution – The analog video standard NTSC was developed in the 1950's. Regardless of a
camera's image quality claims, the video signal is still being transmitted down a resolution-limited
pipe that was invented over 70 years ago. Therefore, resolution is still the primary reason the
industry continues to shift from analog to IP. Consider this: A 1.3 megapixel IP camera is nearly 4

times the resolution of full D1 analog. A 3 megapixel camera is over 9 times the resolution of
analog. Once a customer realizes how much additional detail they can see with megapixel IP
cameras, they soon abandon the notion of analog CCTV cameras.
Another significant advantage of higher resolution is the ability to cover a wider scene. A single
multi-megapixel camera can often take the place of 2 or 3 analog cameras, which makes total
cost of ownership the issue vs. cost per camera. Now there are fewer cameras to purchase, fewer
cameras to install and fewer cameras to maintain. And let's not forgot the risk of inadequate
analog video quality: the cost of not being able to identify a suspect in a criminal activity or not
being able to disprove a slip and fall claim.
Cabling – CCTV cameras require coax cable, which only carries one signal: the video. To power
the camera, you'll need a nearby power outlet or a separate power cable. Or you can use
combined video/power cable, but this further increases the cabling cost. If you want audio or PTZ
functionality, each of these also requires an additional cable. The bottom line: CCTV cabling is
expensive and limiting. In contrast, IP typically only requires a single low-cost network cable for
each camera run. And because IP surveillance networks are decentralized, you need only run
cable to the nearest switch, not to the recording device or server.
Intelligence – CCTV cameras are generally considered dumb devices, meaning they output only
a video signal. With the exception of PTZ cameras, there's no easy way to control the functionality
of an analog camera remotely. In addition, there's no onboard intelligence, such as video motion
detection. IP cameras, on the other hand, are essentially computers with high-end integrated
cameras. Not only can they be remotely configured (e.g., resolution, brightness, frame rate), they
can also detect motion or tampering and act on it by emailing, uploading or recording images or
video to an embedded SD card or external storage device.
IP Camera:
An IP camera has an image sensor much like the analog camera. However, once it has captured
its image, it transmits it as “data” over a network connection. That data is in the form of
compressed video frames sent over standardized networking protocol used for computer
applications which is where it gets its name. “IP” stands for Internet Protocol which is the low-
level language used to transmit data between computers in your home and the Internet. What
this implies then is that the IP camera is like a little computer that you connect to, to access your
video. Indeed, IP cameras are computers and run operating systems not all that different from
your PC. Where they differ is that they are fixed function and their programming cannot be
extended by the user.
Types of IP Cameras:
Decentralized vs. Centralized IP Cameras:
Centralized IP cameras are a network of linked security cameras; however, they are only the eyes
of the security system because a central video recorder that all the cameras link to handles video

recording. Central storage ensures that the security footage remains safe even if the camera is
damaged or stolen.
On the other hand, decentralized IP cameras are stand-alone recording devices. Each records the
video stream in a local storage medium, such as a hard drive or thumb drive. Decentralized
storage ensures that there is very little chance of losing all surveillance and security footage at
once.
Fixed vs. PTZ IP Cameras:
Fixed IP cameras are network cameras placed in fixed positions. Therefore, they have fixed
viewing directions and angles. A fixed network camera is, therefore, used to survey the same
area of a property without ever panning away. Although they are fixed, these cameras may also
be equipped with different lenses to enhance their functions.
On the other hand, a PTZ IP camera can pan, tilt, and zoom using either manual or automatic
controls. This wide range of motion allows one camera to conduct surveillance from different
directions and multiple angles, which makes it ideal for continuously tracking an object of
interest and zooming to investigate.
Dome IP Cameras
Besides the usual box form, both fixed and PTZ IP cameras come in a dome form factor. A dome
IP camera shares most of the properties of a regular, boxy IP camera. For example, a fixed
dome IP camera points only in one direction like a regular fixed IP camera; however, dome
cameras offer certain benefits over regular IP cameras. For example, a PTZ dome IP camera can
swivel 360 degrees.
Components of an IP Camera:
Lighting Controllers:
There are various types however we need to discuss most commonly used terms. There are three
types mono-chromos (Day/Night Only), Color (Day/Night Only) and Day/Night Camera. They
perform different functions with different tools and equipment, some are discussed below:
Low-light Imaging
Low-light imaging cameras work by using image intensifiers. The intensifiers enlarge the available
light to produce an amplified image. This allows the broader image of the low-light scene to be
viewed. These cameras need some light available to produce an image. However, during low-
light scenes, the image they produce is excellent. Low-light cameras have the ability to identify
people. These cameras are a popular choice for homeowners because they are affordable.
Infrared Illumination (Night Vision “IR”)

Infrared illumination combines with motion detection technology to create an effective security
camera. When the camera detects movement, the infrared illumination lights up the scene and
captures the images or may be continuous. These cameras can display detailed images such as
numbers, lettering and objects. Infrared illumination cameras are inexpensive and don’t rely on
ambient light to capture images. Combined with motion detectors, they do an excellent job of
monitoring the perimeter of your concern.
Infrared illumination works with multiple LED lights to transmit images in black and white. Black
and white produces a better quality image. However the ability of infrared lights determine the
area that can be captured.
Thermal Imaging
Thermal imaging technology works by operating on the principle that objects radiate infrared
energy because of its temperature. This type of security camera doesn’t require light to produce
an image. The higher the temperature of the object, the more infrared energy is emitted. The
thermal image is created by the infrared energy. Thermal images produce black images when
objects are cold and white when they are hot. You can find some thermal cameras that project
images in color. Thermal imaging cameras offer a high level of thermal sensitivity.

Lens:
One of the difficult problems when setting up a CCTV system, is choosing the right lens for your
cameras as different lenses give different fields of view, and different levels of zoom. Some of
the higher-end lenses also offer features such as Auto-Iris, and manual zoom/focus adjustment.
Choosing the wrong lens can lead to a camera monitoring too small an area, or conversely not
having enough zoom to capture events with clarity.
Lens size samples:
The following images demonstrate the differences in lens sizes. We set up a tripod 10 metres
from the office door, and mounted 5 High Definition Weatherproof Day/Night cameras, using
one of each of the available 4.3, 6, 8, 12, and 16mm lenses. Aside from the lens size, the cameras
are all identical, and the position of the camera does not change. This guide can also be used for
comparing with lens sizes for body camera lenses.
Adjustable lenses are marked with their maximum and minimum sizes. Examples are 3.5 - 8mm
lenses (of which the 6mm sample above would be roughly in the middle of this range), and
telephoto lenses that range from around 5 to 50mm.
There are once again an ocean to discuss but narrowing it down; customer will ask for following
type most of the time:
 Fixed Focal Length
 Variable Focal Length
 Manual Zoom Lens
 Motorized Zoom Lens
Housing:
Unless physically protected, CCTV cameras have been found to be vulnerable against a variety of
(mostly illegal) tactics
 Some people will deliberately destroy cameras. Some cameras can come with dust-tight,
pressurized, explosion proof, and bullet-resistant housings.
 Spraying substances over the lens can make the image too blurry to view.
 Lasers can blind or damage them. However, since most lasers are monochromatic, color
filters can reduce the effect of laser pointers. However, filters will also impair image
quality and overall light sensitivity of cameras. Also, complete protection from lasers of
any wavelength would require use of completely black filters, rendering the camera
useless.

So in order to protect our cameras in vulnerable environments we use housing, housing is
available for both Indoor/Outdoor cameras. Housing doesn’t only saves our cameras from rigid
attacks but also sometimes acts as extra shield against tough weather conditions.
Sensor:
Lowest end IP cameras use the same sensors as analog cameras. In other words, they have a
resolution of 720×480 or 720×576. Some go as far as even using interlaced sensors. While
interlace is a fact of life in analog camera, we cannot think of any reason to tolerate them in IP
world where interlace only hurts the image fidelity. So where possible, avoid using interlaced IP
cameras and instead, opt for units with “Progressive” sensors.
Video Compression:
Uncompressed video takes considerable amount of data to store and transmit. Even in standard
definition, the numbers can be huge. Take DVD. At just 720×480 resolution, times 24 frames a
second (used in movies), we are talking about 132 megabits/sec of data. If you have a typical of
broadband connection of say, 3 mbit/sec, your link is 40 times slower than what is needed to
watch DVDs without compression!
Luckily, video is very amenable to compression. Frames of video themselves have a lot of
redundancy in them as do sequence of frames. Take a blue sky. Chances are a lot of pixels are
the same and can be described using fewer bits of data. We call this “interaframe compression.”
JPEG is a form of interaframe compression. Send a sequence of JPEG frames and we call that
Motion JPEG or M-JPEG for short. JPEG is very cheap to implement and hence the reason it is
universally offered in IP cameras.
Another form of compression is “interframe” compression. This takes advantage of redundancy
between frames. MPEG-2, MPEG-4, H.264 (also called MPEG-4 Part 10 or MPEG-4 AVC), and VC-
1 are popular compression standards of this type. At high level, these systems perform a similar
function to JPEG in compressing an individual frame. But they also look to see if the current
frame is similar to the one before it. If so, then they only transmit what is different and the
decoder combines that information with the pervious frame to display the image.
For example, imagine a person walking in front of a building. The building is not changing in every
frame. The only thing changing is the pixels describing the person moving. The above systems

divide the screen into blocks and then track whether each block moves. If it has, it then tells the
decoder to move that square, rather than having to retransmit the whole image. The decoder
holds on to the previous frame(s) in order to be able to perform this processing. The amount of
compression is not predictable and is picture dependent. A static image achieves the highest
level of compression. A noisy night-time image with lots of motion will probably be the lowest.
Indoor/Outdoor Camera:
The primary distinction between indoor and outdoor security cameras is the types of external
factors each camera has to be able to withstand. While both types of cameras usually come in
similar styles and with comparable features, outdoor cameras need to be able to contend with
all types of weather and varying light conditions. Outdoor cameras are also more vulnerable to
being tampered with, so they are typically made of more durable materials, like metal, and may
be heavier or even housed in a casing in order to discourage easy removal.
Indoor cameras can be smaller, more lightweight and are usually less intrusive than bulkier
outdoor cameras. Both indoor and outdoor cameras utilize features like infrared, allowing for
clear pictures in low light conditions and easy transitions when there is a sudden change in light-
changing automatically from color images in bright light to black and white when it gets darker.
Dome cameras are also common for both indoor and outdoor use. Dome cameras are designed
to keep the onlooker from knowing exactly where the lens is pointed, which keeps people from
easily hiding from the camera. Domes also provide an extra level of protection for cameras that
are mounted outside. In addition, there are outside cameras that come with blowers and heaters
to provide extra protection against the elements.
If you are looking for a hidden camera that is concealed in something like a smoke detector, exit
sign or clock, it is important to know that most are not weatherproof and therefore not
recommended for outdoor use. Hidden cameras are better for covert indoor surveillance
whereas outdoor cameras are usually noticeable, their very presence being an extra deterrent
for bad behavior.
Recording Devices:
When considering video recording of advanced solutions, installers and integrators have had two
choices: the embedded hardware NVR or a software-based VMS solution. Increasingly there is a
third choice: the security appliance. Benchmark considers the pros and cons of each to see which
offers a greater degree of flexibility. The answer is very tricky as it all depends on your
requirement and type of application.

Then selecting a video management and recording system for advanced solutions, there are three main
options. These are the hardware-based NVR, the software-based VMS and the somewhat newer security
appliance. To describe the latter as a cross between the two would not be unusual, but to our minds it
doesn’t fully explain what the appliance is.
The first of the three choices is the embedded hardware NVR. These standalone boxes support a fixed
number of cameras and typically include management software and integral hard drives. In essence, they
represent a one-box solution. Add a monitor and some cameras, plus connectivity if transmission is
required, and you’re in business.
The vast majority of established brands in the CCTV surveillance sector will offer an NVR. The choices vary
from low cost basic units’ right up to advanced systems.
One negative for NVRs is that the third party products which are compatible with the recorder may be
limited, and in some cases installers and integrators can only use cameras and codecs made by the
NVR manufacturer or their partners.
The second choice is the software-based VMS (video management system). There are a few different
approaches to the delivery of VMS packages; some manufacturers offer solutions that are defined for
various levels of risk (this affects the included functionality and camera count), whilst others offer
unlimited solutions with full functionality, the camera count only being capped by the capabilities of the
server used. Typically a VMS solution will require a license for each connected device. However, this small
fee ensures the delivery of a functional driver. Treat it as an insurance against problems. If a supported
device won’t work, it’s the problem of the VMS Company because they’ve sold the license!
The plus side of a VMS is enhanced flexibility and functionality, allowing the creation of bespoke systems,
plus an open approach to the use of third party devices such as cameras, codecs and additional elements
such as IVA and ANPR.
Typically a VMS is supplied as a software package. The installer or integrator needs to provide a server to
run the software and to archive footage and other data, plus a monitor and cameras, plus connectivity if
transmission is required.

Any VMS provider worth its salt will support installers and integrators with regard to configuring servers
and loading the software, and will offer training as well. However, they also recognize there are many who
want the benefits and flexibility of a VMS solution, but with the simpler approach of an NVR. This is where
the video appliance comes in!
Video appliances are typically pre-configured servers, manufactured by a specialist server company, which
are pre-loaded with a VMS package. This allows the higher flexibility of a VMS solution, packaged in a one-
box offering which is ready to run. The VMS provider will work with the server company to certificate the
application, so the installer or integrator knows that the hardware and software elements will be perfectly
integrated and suited to surveillance needs.
With video appliances, you receive a ready-to-run one-box solution, but with enhanced flexibility and an
open approach to third party devices. However, always check that the functionality and capacity of a VMS
running on an appliance is the same as the specification for the software on its own. Some manufacturers
will limit certain features or camera counts to ensure that the appliance is not pushed too hard. Because
appliances are typically built to a cost, the software might have slight restrictions.
Networking:
Once we have a video image compressed, we need to transmit it where it is going to be viewed
or stored. The favorite method of physical connection is an Ethernet port. Being the most
common interconnect scheme for computers for a number of decades, one gains incredible
economies of scale in this manner. And with advent of Power over Ethernet (PoE), IP cameras
can be powered using the same Ethernet wire.
There is some folklore around lack of bandwidth to distribute video over Ethernet. In reality the
opposite is true. A typical IP camera has a data rate of 2-3 megabits/sec. So even the old standby,
100 Mbit/sec Ethernet has ample bandwidth to carry the signal from many cameras over the
same wire. In reality, you would be using an Ethernet switch meaning each camera gets its own
private 100 mbit/sec so there is no congestion at all. Yes, the final link to the recorder needs to
be able to capture data from all the cameras but with advent of ultra-low cost gigabit Ethernet
switches, there really is no barrier to deployment of large number of IP cameras. And of course,
being “data” and digital, we are immune to noise over the cable, unlike analog cameras.
Modern IP cameras provide a range of interfaces to extract the video from them. The simplest
form is an included web server in the camera which you can connect to using any browser and
view (usually motion JPEG) videos directly.

While operating in the browser provides broad level of compatibility, it can be limiting from
functionality point of view. For this
reason, camera companies also
provide plug-ins called “ActiveX
controls” in Windows lingo, which
are little applications that know how
to talk to the camera. These controls
are like the Flash player used on the
Internet to play audio/video streams.
Next method is through a software
development kit (SDK). This is a
computer library that application
developers use to talk to the camera.
The SDK is used for example by third-
party DVR software to capture video
and control the camera. Without the
SDK, third party integration is not
possible. Many cameras have the
ability to upload their videos directly
to a networked storage device, whether this is a NAS (Networked Attached Storage) or a PC
server. Others can email you select video frames, or “ftp” the stream to an Internet server.
On the control front, that is done through software. Instead of running wires to control the
functions of a PTZ camera, you would use the software interface to send the same commands to
the camera, saving wiring costs.

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