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 video surveillance
system can make your business safer, more efficient, and less
prone to theft and accidents. Specifically, video surveillance
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 video surveillance 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 Video Surveillance Buyer's
Guide will help you understand what goes into a video surveillance
system, how to compaer 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.
Surveillance
Cameras
There are many technical terms and specifications that dealers
will refer to when discussing surveillance cameras as part of
a CCTV system.
The basic
technology behind most surveillance 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 surveillance 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" surveillance 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.
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 surveillance 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 surveillance camera, you need several peripherals
to get your video surveillance system working.
Lenses
As with regular surveillance camera, the lens on a surveillance
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 surveillance
camera: 1/4" lenses work best with 1/4" cameras. It
is possible to use a larger format lens than the surveillance
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 surveillance 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 surveillance
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 surveillance camera and its expected usage.
CCTV
Security Camera Monitors
Selecting a monitor for your CCTV security camera 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 security camera 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 CCTV security
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 CCTV security 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.
Video Security System Recorders
Recording is essential to the effectiveness of any video 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 video security 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 video security 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 CCTV 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.
Video
Security Systems: 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 for your video security system.
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.
