FAQ
Q1. What are the differences in integrators?
Q2. Which is better, coaxial cable or video over unshielded twisted pair (VUTP) for analog cameras?
Q3. Should I buy a system that just supports one type of camera format?
Q4. Are IP cameras better than NTSC cameras?
Q5. Do I need an IR illuminator for night viewing?
Q6. Are indoor cameras different than outdoor cameras?
Q7. What is the value of integrating my video system with an access control system or point of sale system?
Q8. Are there special lenses for night time surveillance?
Q9. How do I view video over poor or low speed links?
Q10. Why do I need an architecture, can’t I just buy a system?
Q11. Is a pan tilt zoom (PTZ) camera better for a wider range of coverage than a fixed camera?
Q12. What is the difference between a DVR and a NVR? Which is better?
Q13. What is better, multiple stand alone systems or an enterprise system for my multi-site coverage needs?
Q14. Can I record video over a wide area network, such as the internet?
Q15. What is the distance I can have a camera over a cable connected?
Q16. What is the difference and value with electronic shutter cameras vs. manual shutter cameras?
Q17. What is the difference and value with auto iris lenses vs. manual iris
Q18. What is the best way to produce video clips from a video surveillance system for long term archive or for evidentiary purposes?
Q19. How should my system scale in number of cameras and in number of locations?
Q20. How should I power my cameras?
Q21. Should I compress my video to obtain a greater number of days being recorded and archived?
Q22. How is Video Surveillance Changing?
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Q1. What are the differences between integrators?
A. There are three major groups of integrators Architect/Integrators, VAR/Integrators, and Integrators. Architect/Integrators typically do not sell or push one type of product; they are agnostic to different technology.
They tend to design/architect solutions based on pure requirements, such as threats and vulnerabilities. VAR/Integrators, or Value Added Reseller/Integrators are pushing a product, a product whose selection is based on markup value.
It is to their advantage to recommend products that they resell to increase their profit. They tend to fit the requirements to a product solution instead of the other way around. Basic integrators work off of other people’s design.
They read the design, buy the equipment, and install per the specifications. This works if the design is done correctly, however there is no real tie between the integrator and the design
Q2. Which is better, coaxial cable or video over unshielded twisted pair (VUTP) for analog cameras?
A. When wiring NTSC or PAL cameras, traditionally integrators used 75 ohm coaxial cable. This type of cable works well however, it has some limitations. It is distance limited (<300 ft), heavy, expensive, and requires BNC terminations at each end. Some integrators use twist-on BNC connectors while others use Crimp type connectors. Twist-on connectors tend to fail over time. Additionally, it is awkward to effectively deploy a proper cable management system in the head-end. VUTP requires the use of two baluns – one at each end – to change the impedance of the cable from 100 ohm to 75 ohm. However, in a typical CAT53 or CAT6 cable, there are four pairs – video only uses one pair so there is sparing built in. Or, the extra pairs can be used for power or telemetry. Additionally, video can be run distances up to 1000 ft with passive baluns and greater than 4500 ft with active baluns. The wire is lighter, less expensive, and has significant standards available for cable management and termination. Finally, should the system transition from analog (NTSC) cameras to IP cameras, the cabling is already in place. VUTP supports either type of camera format.dsdffgfg
Q3. Should I buy a system that just supports one type of camera format?
A. No. The market is evolving, constantly. It would be extremely limiting to purchase a system that supports only NTSC or IP cameras as both have a place in the market right now and there are advantages and disadvantages to both. Since there is (should) no penalty to buy a system that supports both, you should look for that type of system.
Q4. Are IP cameras better than NTSC cameras?
A. When comparing cameras, you must compare at equivalent price levels of both cameras and channels. Price for price, right now, NTSC cameras offer superior image quality, however, those price points are changing. A great deal of the market research and development is on the IP side and those comparisons are constantly changing. However, other factors must be taken into consideration and those include cost and networking impact.
Q5. Do I need an IR illuminator for night viewing?
A. Infrared (IR) illumination offers an excellent supplement
to normal lighting in the absence of normal lighting.
However, several factors must be taken into consideration. IR
lighting tends to get washed out and ineffective when shown in
conjunction with regular white lighting. So adding IR to a
scene that is reasonably well light may in fact, do nothing.
Some cameras and lenses have IR filtering which is turned on and off
based on sensing of what type of light is available. It is important to
choose the correct camera and lens. Finally, there are
different wavelengths and different operating ranges for IR.
Choosing the one that is right for what you are trying to illuminate is
imperative as reflective glare and or washout may occur
.
Q6. What is the value of integrating my video system with an access control system or point of sale system?
A. Security systems, such as video surveillance, are put in
place to counter security threats and overcome security
vulnerabilities. This goes the same for access control
systems. Both of these and Point of Sale (POS) systems also include
auditable logs that also come into play in security system
design. The systems as stand alone, represent effective means
to handle different security requirements. However, by
integrating them, the effectiveness is increased especially in the
post-event analysis capability. All of these are, in fact,
event-based systems. Motion detection is the event by which
the video is activated while passing through a controlled doorway is
the event for access control. By linking access control to video, one
can easily look at all the sensors monitoring an event. By
linking video to POS, you can now look at the item being purchased and
who is buying it instantly
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Q7. Are indoor cameras different than outdoor cameras?
A. For the most part, all cameras are the same.
There are different features (e.g., low light sensitivity, wide dynamic
range) that make some cameras better for outdoor (or low light)
applications, but essentially, they are the same. There are
different lenses that lend themselves better to outdoor applications as
they overcome varied lighting conditions, such as auto-iris
lenses. The biggest difference between indoor and outdoor
cameras are the housings – outdoor must be weatherproof
(check the IP rating), some should have heaters, blowers, and
defrosters, and some must be capable of withstanding the harsh
environments they are put in (vandal proof or bullet proof).
Remember, with enclosures that have heaters, blowers, and defrosters,
you must compensate for this in your power design both in supply and
cabling.
Q8. Are there special lenses for night time surveillance?
A. With the exception of a few key features, the lenses are the same.
The key is to have an auto-iris lens to allow it to adjust for varying
light levels throughout the day and if IR illumination is to be used,
either the camera or the lens should have IR filtering that comes on
and off accordingly. Other than that, for low light
surveillance, a wide aperture lens is preferred to allow for the
greatest amount of ligh
Q9. How do I view video over poor or low speed links?
A. This can be a critical design point. More and more DVS
implementations required remote viewing and management. There
are a couple of important design points. One, to provide for
high quality video archive, you should try and not attempt to record
the video over the low or medium speed links. Even high speed data
links will get overwhelmed with full time streaming recording of high
resolution, high frame rate video. So it is important to design the
architecture such that the recording is done over extremely high
quality data links. Two, viewing is different than recording.
If your architecture supports high quality recording of video local to
the camera, then the remote video doesn’t always need to be
of the same quality. Lower frames per second rate and high compression
can be employed to work within the available bandwidth.
Equally important, if there are multiple viewing stations within a
single facility, which is remote from the camera, then it is important
to establish a single stream of video (over the low speed link) to the
facility, then serve the multiple viewing stations from that stream
locally over a local area network. Dynamic bandwidth
management is an essential component of success for any distributed
video surveillance architecture
Q10. Why do I need an architecture, can’t I just buy a system?
A. Too many organizations simply buy systems. As a matter of
fact, too many designers simply spec a system and have the requirements
conform to the system’s capabilities and
limitations. (This becomes obvious when requirements dictate
16 cameras, the typically limit of a DVR). An architecture helps
identify the true surveillance requirements and ties the technology to
those requirements. Each of those two components are somewhat
independent so as requirements change, it is easy to accommodate those
changes in technology and as technology evolves, it becomes easier to
adapt. An architecture helps protect your investment and
helps avoid proprietary solutions that can hold an organization hostage
to that one brand or one product.
Q11. Is a pan tilt zoom (PTZ) camera better for a wider range of coverage than a fixed camera
A. A PTZ camera is for dynamic surveillance,
meaning actively monitored surveillance where individuals are involved
in the aiming and lensing of the viewing. For many
applications, video surveillance target areas are not actively
monitored by individuals where that is their sole function. A
great example of a good PTZ application might be in a retail store
where loss prevention personnel are following shoplifters throughout
the store to gather evidence against their activities.
Another example would be where a PTZ camera would supplement fixed
cameras in a discreet surveillance application where the incident is
captured by the fixed camera and the PTZ is used to zoom in and
identify the individual. For full time coverage, cameras need
to be aimed and focused on the subject areas, anything less than that
is not full time coverage. Many individuals specify PTZ
cameras as a way of working within the limitations of a DVR that is
channel limited. If they already have 14 channels used
somewhere and need a big parking lot covered, and they only have two
channels left, then they will suggest a PTZ to cover the full
lot. PTZ cameras are typically four times the cost of fixed
(or greater) so without a channel-limited DVR, you can install four
cameras to cover the same area as a PTZ and typically get better
coverage.
Q12. What is the difference between a DVR and a NVR? Which is better?
A. Although somewhat transparent to the end user, NVRs
represent a more open solution, utilizing standard computers and
networks. DVS software can be hosted on any computer technology, can be
easily upgraded, can scale both horizontally (adding servers) and
vertically (upgrading servers), support multi-format cameras, and does
not include costly proprietary maintenance fees.
DVR’s are essentially computers, but the proprietary nature
of them make them very costly and limited for any upgrades,
scalability, and flexibility in configuration. Additionally,
in the evolution of video surveillance, network video recorders
represent where the technology is now and where it is headed. DVRs,
although still very popular, represent a technology phase that has
already been surpassed. Due to the extremely profitable aspect of DVRs
– both in installation and in maintenance – they
are still recommended by many vendors.
Q13. What is better, multiple stand alone systems or an enterprise system for my multi-site coverage needs?
A. An enterprise system offers a couple of advantages over
multiple stand-alone systems. An enterprise system provides
for greater flexibility in how it is configured – typically
any camera from any server can be viewed/managed by any user within the
enterprise. An enterprise system provides for a true single
logon where many stacked DVR type systems may have a single logon
interface, but in fact that is a front end to multiple
logons. An enterprise system can be managed from any single
point within the architecture. Finally, typically, it is loss
costly to deploy an enterprise system over multiple sites than single
standalone, especially when systems management is taken into
consideration. For small, simple installations where a true
single architecture is not required, standalone DVRs or NVRs can work
fine but the organization must understand their limitations.
Q14. Can I record video over a wide area network, such as the internet?
A. . This can be a critical design point. More and more DVS
implementations required remote viewing and management. There are a
couple of important design points. One, to provide for high quality
video archive, you should try and not attempt to record the video over
the low or medium speed links. Even high speed data links will get
overwhelmed with full time streaming recording of high resolution, high
frame rate video. So it is important to design the architecture such
that the recording is done over extremely high quality data links. Two,
viewing is different than recording. If your architecture supports high
quality recording of video local to the camera, then the remote video
doesn’t always need to be of the same quality. Lower frames
per second rate and high compression can be employed to work within the
available bandwidth. Equally important, if there are multiple viewing
stations within a single facility, which is remote from the camera,
then it is important to establish a single stream of video (over the
low speed link) to the facility, then serve the multiple viewing
stations from that stream locally over a local area network. Dynamic
bandwidth management is an essential component of success for any
distributed video surveillance architecture
Q15. What is the distance I can have a camera over a cable connected?
A. For coaxial cable implementations, this is typically 300
ft. For IP implementations, it is also 300 ft, the limit of cat5 or 6
network segments. For Video over Unshielded twisted Pair, this is
around 1000 ft for passive baluns and up to 5000 ft for active balun
implementations. For fiber, it is virtually unlimited but
very costly.
Q16. What is the difference and value with electronic shutter cameras vs. manual shutter cameras?
A .For 99% of applications, lenses with electronic shutter settings are
desired. For some specialized applications, such as license
plate recognition, it may be desired to have a high speed manual
(fixed) shutter settings. The reason is the time it takes the camera to
determine the optimal shutter speed can result in frames
lost. Most manual shutter cameras are also electronic shutter
capable. It may also depend on what type of lens (auto iris or manual),
most cameras won’t allow for manual shutter settings with an
auto iris lens
Q17. What is the difference and value with auto iris lenses vs. manual iris lenses?
A. Auto Iris lenses are great for outdoor application to help
the camera manage light from day to night. Manual iris lenses are good
for fixed light applications such as interview rooms where the light is
a constant. In some applications, auto iris lenses
are not desired outdoors (such as LPR) as headlights can cause the iris
to close and thus miss the license plate.
Q18. What is the best
way to produce video clips from a video
surveillance system for long term archive or for evidentiary purposes?
A. Ideally, the video should be easy to produce and easy to
be provided to who needs it. This usually means the video is
in an open format or provided such that the player is integrated with
the video. If video is produced to optical media (DVD or CD),
then it should fit on that media and any specialized player should also
be provided such that the person viewing it simply needs to insert the
disk into a computer or DVD player and hit play. Digital
media can be large. A typical 90 minute DVD that you watch a
movie on can be 12 GB of data. Compression and resolution settings may
have to be managed to find a trade off between image quality and image
portability.
Q19. How should my system scale in number of cameras and in number of locations?
A. . Linearly. In other words the cost to go between 7 and 8 cameras
and the cost to go between 16 and 17 cameras should be the same or
close. This has a lot to do with channel limitation of DVRs vs. more
open licensing nature of NVRs. However, either application the designer
should have an understanding of near term and long term surveillance
needs. In an enterprise application, theoretically there is no limit t
the number of cameras or the number of server (or number of monitors)
in the architecture.
Q20. How should I power my cameras?
A. Most surveillance cameras, analog or digital, or low
voltage, either 12 VDC or 24 VAC. Either is
appropriate. In the architecture, it is recommended to have
centralized power supply/distribution at the head end to aid in
troubleshooting and management. DC voltage is polarity sensitive and
for some instances, installers reversing the polarity may result in a
damaged camera. Outdoor housings and IR illuminators are
typically 24 VAC so it might be suggested that if outdoor cameras are
used, make the whole system 24 VAC so that you don’t need two
different power sources. Many cameras are dual voltage and
support both. Power can be applied over UTP (for VUTP
applications) up to 300 ft. Beyond that, separate power leads
are recommended and are recommend for any supplemental equipment, such
as housings and IR illuminators.
Q21. Should I compress my video to obtain a greater number of days being recorded and archived?
A. This is a trade off, archive time vs. quality. It really
depends on the application. Typically, we recommend going
with the higher quality and if the archive is important, move it to an
external media such as DVD or network attached storage
device. When designing a system, it is important to have the
flexibility to have compression and/or frames per second adjustable on
a per camera basis and, in some instances, on a event-basis.
In other words, some cameras (covering a door) might not need the same
resolution as those trying to identify individuals approaching a
particular area. Better quality might be given to the camera
trying to identify individuals. Likely, identifying
individuals might be more important during certain times of day or
after certain events (such as a door being opened) and, as such,
compression and frame rate settings might be automatically changed to
accommodate those needs