As soon as you start thinking of setting up your Home Surveillance you
realize that the Camera, however important, is but one element of a System.
Which is therefore the Camera System you should select?
As in so many other fields of human activity, the answer, unfortunately, is
always the same. “It depends…” But this answer gives you freedom of choice and
the opportunity to personalize your selection, making it the most suitable to
your unique circumstances.
The simplest system permits only to monitor camera views in real time (that
is without recording). Such a system is adequate for checking the entrance door
(or any other fixed place), for monitoring the sleep of a baby in the cradle or
the games of the kids in the yard (if they do not run out of view…).
Whenever real time monitoring is not sufficient for surveillance purposes one
should select a suitable recorder. For examining recorded tape footage on the
premises, that is when there is no need to view from a distance, analog
technology based on one of the available types of tape recorders is
adequate.
A tape recorder will be suitable if the time available between cassette
changes (two to four hours) is sufficient to suit your needs. Otherwise special
time-lapse recorders can be obtained that conserve tape by sampling images at
pre selected intervals.
The system becomes more complex if more than one camera sends images to
monitor and recorder. In this case one of the two following solutions is
available. Either one can sample in sequence (using an automatic switcher) every
camera in turn or, using a Multiplexer, one can examine multiple reduced views
on the same monitor.
But if images must be seen at a distance using the Internet, then the analog
technology is not suitable any more. One must go digital to permit manipulation
of images by software as in Personal Computers or in specially designed
dedicated DVR (Digital Video Recorder) hardware.
Besides allowing transmission, digital technology permits software
compression of files resulting in economic use of hard disk drive memory for
many hours of continuous recording.
A PC based digital video system is programmed through software while a DVR is
set up with a kind of hand held remote controller.
A PC uses a digital screen while a normal analog monitor is used for hardware
DVR (although images are digitized for manipulation and recording).
A PC system can easily be expanded later should the need arise, while the
rigid construction of hardware DVR is not readily amenable to further
additions.
To select the most suitable Camera System for home surveillance one should
think about the actual needs and one should answer the following questions as
correctly as possible to narrow down the search.
Is the system needed only to monitor views in real time?
Is analog video cassette recording technology adequate? (No Internet).
How many camera views should be available?
If recording is needed, will sampling of images at intervals be
sufficient?
Is a multiplexer needed for monitoring at once all camera views?
Is there a need to observe the views from a distance through Internet?
Would you be comfortable with PC programming?
In conclusion the selection of the best Camera System for you depends on the
answers to these questions.
