Black & White
(B/W) or Colour?
The trends are using colour system 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 camera?
If you want to mount a 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 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
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 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 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 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. |
