Black & White
(B/W) or Colour?
The trends are with using colour cctv systems these days. The colour cameras
provides clearer identification than B/W . But, in a low light condition
like in 0.1 lux, you may need B/W cameras because they generally
require lower illumination. |
What
parts do I need?
Camera body, lens, mounting bracket, cable, AC Adapter are the basic
parts to produce video and many economic mini camera packages come
with all of these parts. You may add a CCTV monitor (if you
don't use your own TV), quad splitter or switcher to combine more
than one camera, Time Lapse VCR, outdoor housing case and other accessories.
Or, you may choose wireless systems to avoid cabling. Network based
Web Camera Servers are popular for remote surveillance via the Internet
and for convenience in LAN or WAN systems.
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How
many cameras do I need?
You can use
quad
splitter or 4 channel switcher to combine
up to 4 cameras into one monitor or TV. Or, many "observation
systems" come with all in one package, including quad or switcher
built-in monitor and 4 cameras. If you need only 2 or 3 cameras,
a switching system should be enough. If you only need one camera, using
a standard TV rather than special monitor will cut expense. You may
need a 8 channel switcher or multi-plexer to see more than four cameras
on one monitor.
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Do
I need outdoor CCTV camera?
If you want to mount a CCTV camera outdoors you will generally need to
use an
outdoor housing case, with or without heater and/or blower. The heater
and/or blower built-in housing cases generally require separate power
supply. Some cameras are made water resistant and don't need separate
housing cases. Some of them also have removable sun-visor covers.
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Do
I need infrared CCTV camera to see in total darkness?
Commercial infrared cameras, some of which are also water-resistant
for outdoor installation, can see up to 30ft distance in total darkness.
If you need to see farther, you may need professional infrared illuminators
but they are usually expensive and complicated to install due to
its emission of heat. Infrared cameras work as ordinary video camera
during daytime. Most colour infrared cameras work as B/W ones at
night. Minimum
illumination
for most B/W cameras these days is 0.1 lux so you will not necessarily
need infrared cameras or illuminators if there is some kind of ambient
lighting.
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What
angle of view do I need for the lens?
Widely used and recommended angle of view of the lens for surveillance
purpose is 72o to 78o Narrower will give you clearer pictures. Wide
angles like 92o can cover more area but it may not contain the required
detail or may be distorted.
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Do
I need zoom lens?
A manual zoom lens of, for example, 3.5 ~ 8.0mm will allow you to
manually adjust angle of view from 3.5mm to 8.0mm. 3.5mm equates
to about 90o of diagonal view angle on 1/3 " sensor camera and
8.0mm sees about 38o. Auto zoom lens can be adjusted at the control
centre or from your computer. |
Do
I need DC drive auto iris lens?
A little of auto iris functions are built-in in most of cameras included
in most observation systems today. But, when you use professional
cameras you may need to separate DC drive auto iris, a motorized
device to meet the changes of lighting condition of the sun. Generally,
auto iris device is not necessary for indoor application with artificial
lightings.
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Do
I need pinhole lens?
A pinhole lens with a tiny opening can be hidden easily in a wall
or ceiling or other objects. Many economically priced mini
cameras have built-in pinhole lens . A pinhole lens for professional
camera is very expensive.
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What
monitoring system do I need: professional CCTV monitor or standard
TV?
If you use 1 camera, a simple TV (which has RCA
video input) is definitely recommended. Even for more than 1 camera,
if you use combiner like quad splitter or switcher, a TV would be
fine. But, for special features like slave video output (to be connected
to additional monitor), alarm systems or for packaged observation
systems, you may need professional CCTV monitors. |
What
type of CCTV monitor do I need: quad screen or single?
Unless it is necessary to see four pictures at the same time on quad
split screen, a
switching system which shows the pictures one by one (you can control
dwelling time) is recommended for its larger image.
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What
size of CCTV monitor do I need?
12" was the popular size during over the years but these days,
14" for colour and 17" for B/W have become very popular.
Or, 4" LCD monitor to place on the desk is another choice. |
What
video transmission is required: wireless, coaxial or multiple
wire (DIN)?
Wireless
systems can be convenient to
avoid cabling works, but can
be affected by high voltage
power lines nearby, unseen
razor waves, huge machines
like lathe, metal walls etc.
Some wireless systems transmit
locally up to 300ft and others
up to 700ft. Coaxial
cable is conventional in this
field and proper for professional
cameras. It goes up to 450ft
without losing the picture
quality. Multiple wires like
DIN carries not only video
but also audio and power. It
can be extended up to 250ft.
For remote surveillance, you
should consider web cameras.
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Is
a power outlet located close to the CCTV camera?
Or, should the power be supplied from the monitoring place?
For professional cameras, the
power
source is better located close to the camera. You may use 12VDC AC
adapter if the camera is installed indoors and if the power outlet
is within 5ft. If a professional camera is installed outdoors or
the power outlet is located far away, you should use 24VAC AC Adapter.
For DIN cables, which come with pre-packaged
observation systems or mini camera package, the power source can
be close to the monitoring site, but the distance from the power
source to the camera should be less than 250ft.
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Do
I need video amplifier?
When you need to send the video image more than 250ft on mini
DIN
or RCA cable, or 450ft on coaxial cable,
you will need to use video amplifier. You may also need a video
amplifier when you want to connect one camera to 2 monitors.
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Do
I need time & date generator?
Many observation systems have
built-in time & date generator. But, most mini cameras don't
have them and you need one if you want the time & date shown
on the monitor. Time Lapse VCR usually has built-in time/date generator. |
Do
I need motion detection? alarms?
In many cases, the motion sensors are possible to connect to existing
CCTV systems however they are difficult to sight correctly. However,
in digital video recording systems, where the motion detectable area
can be assigned with software using a computer monitor, motion detection
is simple and easy. |
Do
I need Pan, Tilt and/or Zoom control?
Pan, tilt and Zoom functionality is required in special circumstances
and is generally expensive. There are however some systems with built
in PTZ which is easy to install, maintain and control. |
Do
I need to record the pictures?
On conventional Time Lapse VCR or DVR (Digital Video Recorder)?
Conventional
Time
Lapse VCR, even though inconvenient to review the recorded pictures,
is surely economical than DVR (Digital
Video Recorder). DVR is getting more and more popular for its convenience
and picture quality. (Standard home VCRs are not good to run 24 hours
a day and some are only for play, not being able to record.)
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Do
I need computer based observation system?
With a video capture card which converts analog signals to digital
ones, you can connect any CCTV video camera to the computer if it
has enough capacity to handle the video files. The more common method
is to use
web
cameras which run fast over the Internet or Intranet (LAN
or WAN) with small file sizes. Many so-called "PC cameras" uses
C-MOS chip instead of CCD chip and also requires separate software. |
