Video
Surveillance Introduction
From
a single camera and monitor to complex video surveillance
systems with hundreds of cameras, multiple operators, and
digital recorders, closed circuit television (CCTV) systems
can provide security for a wide range of businesses.
A
good CCTV system can make your business safer, more efficient,
and less prone to theft and accidents. Specifically, CCTV
can provide many benefits:
-
reduce shrinkage by catching shoplifters
- deter potential thieves
- monitor cash registers
- record evidence to prevent bogus accident claims
- identify visitors and employees
- monitor hazardous work areas
- increase security in and around business premises and parking
lots
- meet insurance requirements
The
most basic CCTV setup would be a single camera connected directly
to a monitor and a recorder to store the video. While a setup
like this could help security in some cases, it is unlikely
to be enough for most businesses. Most situations call for
multiple cameras. In some cases, you may even want a moveable
camera to cover a large area. This BuyerZone.com Buyer's Guide
will help you understand what goes into a CCTV system and
how to make a successful purchase.
Evaluating
your CCTV needs
Before
starting to compare systems or choose potential vendors, sit
down and consider your CCTV needs carefully.
First,
consider what you want to monitor. General comings and goings?
Vehicles? Do you want to see faces, merchandise, crowds? Once
you decide what you want to see, choosing components will
become easier.
Next,
decide what picture quality you need. Quality can refer to
both how detailed the image is and how fast the frame rate
is. Frame rate is simply a measure of how many individual
pictures make up the video. "Full motion", what
you see on television and on VHS tapes, is 30 frames per second,
or fps. Most often, security systems record at slower rates,
which result in more jerky-looking images but saves tape or
hard drive space, allowing longer periods of time to be recorded.
Think
about how your system will be monitored. Will you simply record
at all times, and only review the tape when a problem occurs?
Or will you have a dedicated employee watching for trouble?
Also, with multiple cameras, you have the option of connecting
each to its own monitor, or combining multiple images onto
one monitor.
You
should also decide whether your priority is to deter potential
crimes or to catch perpetrators. Both can be important, but
your priority will influence your purchasing decisions. If
you are more interested in deterring certain activities, large,
visible cameras are your best bet. Trying to catch criminals
on tape without them being aware of it requires hidden cameras,
which cost more both for hardware and for installation. If
your monitoring target is internal, you run the added cost
of having to hide and secure the recorder and monitor as well.
Security
cameras
There
are many technical terms and specifications that dealers will
refer to when discussing security cameras as part of a CCTV
system.
The
basic technology behind most security cameras is the Charge
Coupled Device (CCD). CCDs convert the images that come through
the camera's lens into electronic impulses. CCDs provide a
good combination of low price and quality picture for security
applications.
Camera
formats are measured in inches: most cameras fall between
1/4" and 1". This refers to the usable image size
created inside the camera. For most security systems, a small
size is fine - 1/4" or 1/3" cameras dominate CCTV
sales. Larger formats do not necessarily result in better
images, but can be advantageous in dimly lit situations since
they are able to gather more light.
Color
vs. black and white
Since prices have dropped significantly, many businesses today
opt for color cameras over their black and white models. For
security and evidence purposes, color cameras are better--sending
security guards after "the man in the blue coat,"
for example, is much more difficult when you can not tell
what color the coat is.
While black and white cameras can operate better than color
cameras in extremely low light situations, most small to medium
sized businesses use CCTV in well-lit indoor environments.
In addition, many high-quality color cameras today can switch
to black and white mode when necessary. Some vendors do not
even sell black and white cameras any more.
Resolution
Resolution refers to how detailed a picture the camera can
see. The measurement to look for is horizontal TV lines (TVL).
A normal CCTV picture is around 350 to 400 TVL, with high
resolution getting up to 480 or 500. Upgrading a camera's
resolution can cost as little as $50.
You need to make sure your entire system is capable of supporting
that resolution. If your VCR records 350 lines and your monitor
displays 400, the money you spent to upgrade to a camera with
500 lines is completely wasted. In the end, the small cost
to upgrade your camera may be multiplied by the costs to upgrade
other equipment.
Note:
do not be impressed by pixel measurements in the hundreds
of thousands. TVL is a more consistent measurement.
Other
specs Signal to noise ratio (s/n) indicates how much "signal,"
or actual picture information, the camera transmits, as opposed
to "noise," which comes across as static. A s/n
ratio of 40db indicates that the signal is 100 times the noise,
which results in an acceptable picture with some fine grain
or snow. 30db results in a poor picture, and 60db produces
an excellent picture with no static visible. Keep in mind
that noise can be introduced by other components in addition
to the camera.
Sensitivity to light is measured in lux. A sensitivity of
2 lux means the camera can see fairly well by the light of
a 40W fluorescent bulb; 0.5 lux cameras can make out images
outside on a dim night. Your needs will depend on the lighting
in the area being filmed, but lux ratings should not be the
most important aspect of your camera decision.
Surveillance
Camera Peripherals
Along
with your CCTV camera, you need several peripherals to get
your video surveillance system working.
Lenses
As with regular cameras, the lens on a security camera determines
how wide an image is created and how much light is let in.
Lenses are generally sold separately from cameras.
The lenses you purchase should match the format of your camera:
1/4" lenses work best with 1/4" cameras. It is possible
to use a larger format lens than the camera calls for, but
it is not recommended.
You
also need to decide what type of lens you need. Fixed focal
length lenses offer only one set field of view and are the
least costly. To change the resulting image, you need to switch
lenses. Variable focal length lenses and zoom lenses offer
greater flexibility, allowing you to adjust your image's field
of view. Motorized zoom lenses, the most costly type available,
give you the ability to control your cameras remotely. If
you want to zoom out for general surveillance and in for detail
when you spot suspicious activity, motorized zooms are the
way to go.
If
you will be using the CCTV camera outdoors, look for a lens
with an automatic iris. As in the human eye, the iris of a
lens is what controls the amount of light coming in to the
camera. Automatic irises can significantly improve performance
for outdoor cameras, where light levels vary considerably.
However, you can save money and use a manual iris lens when
the scene illumination never changes, for example in an illuminated
store or office.
Pan,
Tilt, Zoom
For advanced security applications, you may want a pan, tilt,
zoom (PTZ) camera. With the right equipment, a camera operator
can pan (scan left and right), tilt (look up and down), and
zoom in and out. The significant catch is the cost: PTZ systems
are considerably more expensive than fixed cameras. Housings
Cameras may need to be protected from potential vandalism
or from the elements. Housings can range from simple coverings,
to impact-resistant protection, to outdoor housings that include
heaters and blowers for cooling. A more specialized type of
housing is the dome: tinted Plexiglas hemispheres that prevent
subjects from seeing which direction a camera is pointing.
Choose the right housing based on the placement of the camera
and its expected usage.
Surveillance camera monitors
Selecting
a monitor for your CCTV system is a relatively minor decision,
but there are a couple of important points to keep in mind.
First,
make sure to purchase a monitor specially to handle the type
of use it will receive. Televisions are not good monitors,
since TVs are built to be on for a few hours per day, not
the 8 to 24 hours per day they will endure. In some cases,
computer monitors do make acceptable substitutes. Flat-panel
LCD screens make great CCTV monitors for larger systems because
they take up little space, have excellent resolution, and
generate less heat than regular monitors.
As
discussed earlier, make sure your monitor resolution matches
your cameras. Buy a monitor with lower resolution and your
camera's capabilities will not come through; buy one with
higher resolution and you are throwing money away. And of
course, make sure you buy color monitors if you opt for color
cameras.
Also
consider the size: a 9" monitor may be sufficient if
the operator is sitting directly in front of it, but a 15"
monitor is the smallest you should choose if you plan to combine
images from multiple cameras onto one monitor. Merging multiple
images onto one screen can be an effective way to save space,
and appropriate if there is a dedicated employee who has the
ability to zoom in on suspicious activity.
Security
system recorders
Recording
is essential to the effectiveness of any security system.
Without recording, you need to have an employee watching a
monitor at all times - hardly a cost-effective solution. And
even if you spot suspicious activity, without a recording,
you have nothing to use in court.
Almost
all CCTV systems include some sort of recorder to store the
images the cameras capture. Only a few years ago, the universal
solution was the familiar VCR. However, the introduction of
digital video recorders (DVRs), which record onto hard drives
instead of tape, has dramatically changed the situation.
DVRs
offer so many advantages over VCRs that they have rapidly
taken over as the CCTV recording solution of choice:
·
Ease of locating events - Instead of fast-forwarding through
hours of tape, DVRs can instantly retrieve images from any
specific time or date, or automatically skip to the point
on a recording when something changed.
·
Storage quality - Like all tapes, video cassettes start deteriorating
almost immediately once you record on them - and the problem
gets worse every time you reuse them. DVR recordings have
no degradation at all since they are stored onto a hard drive.
·
Multitasking - While analog VCRs can either record or play,
most DVRs can do both at the same time, letting you review
images while still recording.
·
Smart monitoring - The DVR can be set to take one picture
per second or less - just enough to create a running record.
However when it detects motion, it can automatically bump
the recording speed up to full (30 frames per second), getting
every detail of the unauthorized activity.
For
businesses that do not want to constantly change tapes, DVRs
are definitely the way to go. While security VCRs usually
offer a time-lapse mode that lets them for long periods of
time, the resulting images are not a good record of events
- they record only one snapshot every eight seconds. To get
higher quality, you need to change tapes every day or more
often. DVRs, on the other hand, can record for weeks or even
months.
DVRs
are more considerably more expensive than VCRs, which is their
only major drawback. However, the DVR prices have fallen considerably
over the last year and will continue to do so. Already, low-end
DVRs and high-end VCRs are in similar price ranges, and most
manufacturers have stopped introducing new VCR models. Despite
the increased cost, we recommend CCTV system buyers purchase
a DVR whenever possible.
Choosing
a DVR
As part of your CCTV shopping preparations, decide how much
quality you need out of your recorder. There is no magic number
or spec here: you need to decide how "good" the
recorded picture needs to be, either for your own use later
or possibly to use in court. Once you decide this, you will
be able to look at samples on the DVRs you are evaluating
and see if they meet your standard. Vendors may be eager to
throw compression settings, pixel counts, and other statistics
at you - but those numbers are irrelevant if the picture itself
does not offer the detail you need for legal or investigatory
purposes.
The size of the hard drive will dictate how much you can record.
On the low end, an 80-gigabyte (GB) hard drive will store
about five to eight days of full-motion video from one camera.
Most of the time you will not be recording full motion, so
this is much more than it might seem. For most businesses,
spending a little extra to get 120 or 240 GB is a worthwhile
investment. Units expand up to 1.2 terabytes (1,200 GB), which
can store many cameras' worth of data for long periods of
time.
Replaceable
hard drives are a cheap way to boost storage capacity. With
some DVRs, you can buy additional hard drives for as little
as $150 and swap them in and out as you need. This gives you
the advantage of being able to store your data separately
from the main security system.
You
will also need to consider how many cameras you want to connect
to the DVR. Keep your future expansion needs in mind - buying
a higher-grade model to get more inputs and more storage space
can save you considerable money in the future. The DVR will
also function as a multiplexer, putting up to 16 cameras on
one display and allowing operators to call up any one image
for closer inspection.
Also,
if you ever have to use your security images - in court or
in other ways - you will need to be able to export the video.
This is an important consideration: some systems let you create
industry-standard .avi files, which can be played on any PC,
and burn them to CD. Others only allow you to export proprietary
formats that can only played on the same brand player. Most
DVRs do offer the option to connect a standard VCR - this
allows you to simply tape the digital recording onto a standard
VHS cassette.
Choosing
a VCR If you decide to save money by going with a VCR, make
sure you purchase a model built for security system usage,
not a consumer VCR. Purpose-built security VCRs offer far
more reliable operation than home models, so they can stand
up to constant operation.
The main feature to look for in a VCR is how many hours it
can record: models range up to 960 hours on a standard tape.
Remember, though, that these extended recording times result
in fewer frames per second.
Be
aware of the hidden and ongoing costs of VCRs. Buying, rotating,
and replacing VCR tapes can be expensive and time consuming.
Constant usage creates quite a bit of tape debris inside the
machine, requiring expensive regular maintenance. And in addition,
if you have multiple cameras, you will need a multiplexer
- a separate piece of hardware that combines multiple video
images into one - to avoid purchasing a separate VCR for each
camera.
Connecting
your CCTV system
There
are several ways to connect cameras to the rest of your CCTV
system.
The
most common is standard coaxial cable, the same cable used
to connect video equipment in your home. Some installers use
unshielded twisted pair (UTP) cables, like the CAT5 cable
used in many computer networks, because they can reduce interference
caused by electrical currents. A simple switching device called
a balun can be used to connect coaxial lines to UTP, so you
can combine both in a single system. UTP is cheaper than coaxial
cable, so for very long runs, this may be an advantage.
Casinos
or banks with complex systems consisting of many cameras may
want to upgrade to fiber optic connections. With this setup,
bandwidth is considerably greater, allowing many signals to
be carried on the same wire. In addition, security is improved
because tapping a fiber optic line is very difficult to do
without disrupting the signal.
Wireless
In most cases, wireless connections are not recommended for
video surveillance systems. While wireless technology has
taken off in recent years, it simply has not reached the level
of reliability that CCTV users demand. The frequencies they
use are subject to interference from cordless telephones,
air conditioning, fluorescent lighting, and almost anything
with an electric motor. Users will have to expect interference,
usually resulting in a snowy picture. In addition, cameras
need electrical power - so you will have to run one wire to
the camera even if the video connection is wireless.
There are situations where wireless is the way to go: connecting
across a public street, for example, where digging a trench
is not a practical solution. Wireless systems are also better
suited for rural areas, where there are fewer potential sources
of interference. In these cases, wireless transmitters can
make expensive or potentially impossible installations feasible.
Installation
of wireless systems requires specific expertise to diagnose
problems and fine-tune the setup, so make sure your vendor
is experienced with wireless setups if you choose to go this
route.
Choosing
a CCTV system integrator
The
overall success of your CCTV system can hinge on the expertise
of the installers who set it up. There are many important
factors to take into consideration that require an expert
understanding of lighting, optics, wiring, security, and more.
In other words, your experience connecting your home TV to
the DVD player does not mean you should set up your business
security system!
In
the CCTV industry, businesses typically buy from integrators
or dealers. These vendors usually work with multiple manufacturers
to offer a range of products, as well as installation and
support. As with most business purchases, there are several
key factors to look for when choosing a CCTV vendor.
Experience
A vendor's experience in the industry is a significant indicator
of the firm's reliability and long-term stability. You will
want to be able to work with your chosen vendor on an ongoing
basis as you expand or upgrade your system, so choosing someone
who will be around next year is important. Specific experience
with businesses of your size and in your industry is also
desirable: large warehouses may present problems that a vendor
who specializes in small retail shops may not be prepared
to address.
Installation
The quality of a CCTV installation can have lasting effects
on your business. Qualified installers will not take a standardized
approach to installation: they will analyze your needs and
make sure you get a system that is customized to your location
and business needs. They will also provide enough training
and documentation to make sure your staff fully understands
the operation and maintenance of your system.
Facilities
Visiting vendors' facilities can be a great way to get a sense
of their operations. You will be able to check out their repair
shop and get a sense of how busy they are. You may want to
ask for an organizational chart or a tour of their help desk.
Depending on your support needs, proximity may or may not
be important to you - if you plan to rely on telephone support
and shipping components back for repair, it will not matter,
but if you expect field technicians to come to you, distance
from the vendor can be a factor.
Demonstrations
Nothing will give you a better sense of how well a CCTV system
achieves your goals than seeing it in action. Some vendors
conduct on-site demos, which gives you the added advantage
of being able to see how the hardware looks in your location.
Others will invite you to try the system in their office,
which gives you that facilities tour we discussed, or will
set up on online demo, which is helpful if you plan to view
images remotely.
References
Another familiar way to investigate CCTV systems integrators
for your business is to ask for references to other customers
- make sure to ask for references that are in business similar
to yours. Of course, you will be referred to the vendor's
most satisfied customers, but you can still learn quite a
bit from them. Here are some sample questions to ask the references:
-
How has the CCTV system accomplished the goals you set for
it?
-
Are you happy with the overall quality of the images, both
live and recorded?
-
Was the initial installation sufficient for your needs? Or
did you have to add components or upgrade?
-
What do you wish you had done differently?
-
Have you needed any support or repairs? How did the vendor
respond?
-
Do you know of any one else who uses this system? This can
get you additional references to speak to, some of whom might
be more candid.
-
If you had to say one negative thing about the system/dealer,
what would it be?
Video
Security Systems Pricing
There
are many components to a CCTV system: cameras, monitors, recorders,
and cabling to connect the system. Add in the need for a quality
installation, and it should be apparent that shopping by price
alone is not a good approach. Some dealers will put together
low-end packages to try to lure price-conscious shoppers -
these systems suffer from lower quality, shaky reliability,
and will not last for years and years the way higher quality
systems will.
On
the Internet, you can find complete CCTV packages of 4 to
16 cameras, including a monitor and VCR. Often they look like
great deals - and most of the time, they are too good to be
true. Low-quality components and a lack of support combine
to create an offer that can do more harm than good to your
business.
A
very rough rule of thumb to use for pricing a complete, installed
system is $500 to $1000 per camera, plus the cost of your
recording device. This depends quite a bit on the types of
hardware you choose and how you set it up - read on for a
more thorough breakdown.
Cameras
and lenses
Basic CCTV cameras are not very expensive. Because the hardware
cost is fairly low, it is worth spending a little extra money
to get better system performance. Brand name cameras can be
found for $150 to $250, and are often a better investment
than a no-name camera. Prices vary according to features as
well -- larger formats, higher resolution, and better sensitivity
all drive prices up.
Hidden cameras, concealed in everyday objects like clocks,
smoke detectors, and calculators, run $200 to $400. PTZ cameras
are far more expensive, running $1,500 to $5,000 for one camera
and the controller. If you do not have an operator to run
a PTZ camera, it is rarely worth the expense.
Remember
that in most cases you are purchasing a camera without a lens,
so there is more to spend before you get a workable system.
Lens prices vary widely. Fixed focal length lenses can go
for $100 to $300 depending on size and whether they have a
manual or auto iris; automatic zoom lenses can be between
$800 and $2,000.
Recording
devices and peripherals
This is another area where your needs will determine how much
you spend. DVRs generally start at $800 to $1500 and get more
expensive the more memory and inputs you add. If you are on
a tight budget and willing to invest in fading technology,
good time-lapse VCRs designed for security use start at $300
to $400 and go up to $600 or more.
Housings can cost from $25 to $200, depending on the degree
of protection they provide.
CRT
monitors can go for $150 to $500 and flat panels range from
$300 to over $5000. Both are heavily dependent on screen size.
Warranties
As with most modern electronics, CCTV components are generally
very reliable, especially if you are purchasing industry-recognized
names. If they are going to fail, they will almost always
do so within the first 90 days, while covered by the manufacturer's
warranty. In most cases, it is not worth purchasing the extended
warranty coverage that vendors will offer you.
However you may want to consider a maintenance plan. Having
your vendor regularly come in to clean and test your system
can improve the overall performance and ensure that any problems
that do occur are caught quickly.
Security
camera buying tips
-
Know what you want to see. Knowing exactly what you want to
see in the monitor and on recordings - both the scene and
the quality - is the single best way you can prepare for
-
Avoid dummy cameras. While they may deter some problems, they
also can create a legal liability by creating an expectation
of safety when none exists.
-
Put up signs. Highly visible signage that lets customers and
employees know that they are being filmed can greatly increase
the deterrent effect.
-
Do not record audio. Most CCTV systems do not include audio
monitoring for the simple reason that it is generally illegal.
People in public places can be videotaped without their consent,
but their voices can not.
-
Buy for the right reasons. Using a high-tech solution to solve
a low-tech problem can result in wasted money and effort.
If you have vandalism problems in a parking lot, adding lights
can be a far cheaper and more effective solution than installing
cameras.
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