What I Learned About Security
Cameras
I installed a security camera
system a few years ago and
that’s when and how I got my education in the subject.
I’ll share what I learned with you but be
warned, if this is not an interesting topic for you, read something
you’ll
enjoy, like, “Robert’s Rules of Order”.
I installed a complete “home”
DVR system (digital video
recorder) that came with several cameras, the DVR, software, wires and
everything I would need. I
can watch my
cameras on my TV, laptop, phone and at home or anywhere in the world. It stores video for about
three weeks and it
sends photographs to me by email when certain alarm events occur. I’m sure there are
commercial systems and CIA
systems that exist but my system cost less than $1,000 and that is the
level of
product I will discuss here.
While my system is less than
five years old, there are two
newer generations of the system on the market today.
The first generation after mine uses 960h
picture quality and the current standard uses 1080p picture quality. To put it in context, my
system provides the
video quality similar to the very first camera phones, you know, those
old flip
phones or about 1/4 Megapixel. 960h
is about 50%
better. 1080p is
roughly 2.1 Megapixel
which is about 10 times or 1,000% better than my system.
That’s still not very high resolution considering
what your iPhone or
Android can shoot. But,
recording and
storing 8 or 16 cameras, 24/7 for three weeks at 6 or 10 Megapixels
would
require a MASSIVE hard drive. The
systems that support Megapixel cameras often use the term “Network
Video
Recorder” or NVR to describe their high end DVR.
(see: http://www.security-camera-warehouse.com/knowledge-base/comparing-420-480-600-700-tv-lines-php/)
There are other options.
Some people use Game Cameras, cameras that are
designed to be used in
the woods by hunters to record deer and hogs as they eat the food the
hunter
puts out to attract them. A
very cheap
game camera produces 2 Megapixels and a very good one produces 14
Megapixels. But,
there are two other features that are
important on game cameras. Many of them do not use invisible
infra-red flashes
and most of them do not shoot the first picture very quickly. In a security setting, it
is possible that
your “game” will be out of the frame before your game camera gets off
the first
shot. And, if it
shoots a visible flash,
your “prey” may come back and modify your camera for you. The 14 Megapixel camera I
mentioned shoots
its first photo in .2 seconds which is very fast for the category and
it shoots
a “black” infra-red flash and costs under $200.
It is manufactured by Bushnell.
The problem is that it is not networkable. About once a week you need
to go out to the
camera and remove the SD memory card and review over 1,000 photos. And, by the time you buy
eight of them you
will have spent more than I did on my system and you will be very busy
reviewing photos.
Another
option is the Net Cam. There
are several versions of these by
various manufacturers with various software features.
Google owns a company, “Nest” that makes such
a camera and it produces impressive daytime and night time photos with
sound
and it records video through your WIFI up to the web. That’s a cool
safety
feature because once the video is on the web, a thief can steal the
camera but
not the video. But,
they only store the
video for a week so if your vacations are longer than a week, you may
return to
an empty house and no video. Other
companies sell similar equipment and services but probably not higher
quality
video. One other
detail, these cameras
are not weather proof so you will need some kind of weatherproof
housing. You can
buy these cameras at Best Buy, Wal-Mart
and Amazon for about $100 but the web recording service costs about
$10/month. Some of
the cameras in this category allow you to record on
your desktop hard drive at no cost.
We need
to discuss Infra-Red technology (IR). These
cameras do not use IR heat
technology, which often requires cryonics or an ultra cold camera and
costs
millions of dollars. These
IR cameras
have LEDs that put out light in the 840 or 960 nanometer (nm) range. The human eye can only see
to about
700nm. These LEDs
produce a spectrum of
light and usually the 840nm range reaches into the 700nm range so the
LEDs appear
to glow orange, similar to a cigarette and are thus visible. The point of IR is to be
invisible so it is
important to be certain you are getting cameras in the 960nm range. I’ve learned that if the
box is not marked
960nm or “Black Infra-Red” or “Invisible Infra-Red”, it’s not invisible. Don’t buy it.
IR is
not the answer to seeing in the dark.
IR is just a LED flashlight that the camera
is designed to see and the eye can’t.
My
experience is that the practical useful distance range of the LEDs is
about half what
they are marketed to be. Most
are
advertised to be good up to 60’ and some up to 90’.
Figure
they are good for half of that and even then, often the fringe around
the edge of the picture will be darker than the middle.
An
alternative to IR is Low Lux. Lux
is a unit of measure of illumination.
As a practical matter, don’t buy a camera
that is rated less than .0001 Lux.
These
cameras are designed differently than the IR cameras and most of them
are sold without the lens. This
gives you
the opportunity to buy a zoom lens or wide angle lens or just a lens
that is best
for your application. These
are referred
to as “box cameras” and they are not weather proof, you will need a
weatherproof enclosure to use them outside.
Unless you own a bank, you probably will be using
these outside.
There
are system features that you need to understand:
Motion Detection
Motion detection in a camera is done by comparing the
previous video frame with the current one and if they are different, it
triggers your motion alarm. This
means,
if the wind blows branches or leaves or the neighbor’s garbage or the
sun comes
out from behind a cloud, your camera will have detected motion. Even a bird flying in or across the
field of view will trigger the motion detection. Most
systems have a system of blocks that you
can select on your screen so that you can turn off motion on parts of
your
screen and not on others. As a practical matter, this type of
motion detection is likely only useful indoors in a controlled
environment.
NO
and NC Alarm Interface
This is a connection option to your DVR that will accept the
output of external devices, such as door switches, magnetic switches,
PIR
movement detectors, etc. Most
systems do
not have this option but it is very handy if you are serious about a
multifaceted
security system. (NO means Normally Open and NC means
Normally Closed. This is common technology in alarm systems.)
These devices are ususally PIR
motion detection, laser trip wire or metal detection for vehicle
detection. When triggered, these devices transmit to their
base station which then triggers the DVR if it is wired into it.
The DVR senses the alarm event and takes pictures from
predetermined cameras and emails the photos to the administrator.
Facial
Recognition
Some systems claim to be able to differentiate between a human
face and a dog or leaves. I
have no
experience with this option except that most of the time the person I
am
watching in a video of interest does not show their face except for
fleeting
moments.
Remote
Access
With the exception of the NestCam, you will need to know how
to configure your router if you want access to your cameras remotely. If you have set up a
router before and are
just “proficient”, you likely will be able to do this but, it will take
the
better part of a Saturday.
Covert
Cameras
You can buy cameras that look just like a smoke detector or
PIR movement detector or digital clock that tie into the DVR systems or
work
stand alone. My
experience though, is
that you want to see the crooks before they
get into your house and you have your home alarm
system set to go off as
they enter. To me
it
is pointless to be able to see a crook rifle through your wife’s jewelry. And your
wife may not be too happy with you when she finds out what else you
have
captured on that camera. Use
these
cameras for monitoring infants or baby sitters or your most vulnerable
entry
point, not your hallway or bedroom. License Plate Cameras There
are systems that are specifically designed to read license plates.
The cameras are most often used by auto reposession companies and
Police departments. The cameras are ususally mounted on a "bird
dog" vehicle and can log thousands of license plates a day. A repo
company would drive through mall parking lots, large office
parking garages and through rush hour traffic. The Police use them to
look for wanted vehicles. Home Owner's associations use the
systems to authenticate vehicles before letting them through a gate or
the entrance to a sub-division.
My experience is that you need
a mixture of technology. You
need the highest megapixel cameras you
can afford but the video probably will still not identify who the thief
is or their
license plate. You
will probably want a
game camera for the identity and the video to learn what they did. You will want IR cameras
in dark places close
to your house and low lux cameras for looking out into the street or
cul-de-sac.
Think
twice before you put in a camera system. The night is
alive with activity and you may sleep better not knowing what is going
on in
the dark outside your house at night. And, a camera system absolutely does not
replace an intrusion alarm.
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