Today’s quality CCTV systems are still for the most part
based on analog cameras, IP cameras
are being used for those needing better quality images
or a network based system.
With all of the aggressive advertising we see today on
“high resolution” analog cameras, we must
not forget that these cameras still send video via a
coax cable to the DVR using a carrier defined
as NTSC, also know as 525/60.
NTSC only has 486 horizontal lines in its Active Area, a
NTSC video signal also includes extra
vertical sync lines, which are basically just filler
timed to allow the electron guns in a CRT
television time to reposition themselves at the top of
the screen. There are 39 vertical sync lines,
resulting in a total of 525 lines (486 + 39).
Therefore if a camera can produce 1000 lines of
resolution, and it is to be connected to a
recorder via coax or twisted pair using a conventional
analog signal, the result resolution is 525.
In order to break the 525 barriers, there have been many
attempts. The most successful to date
has been the use of IP cameras. IP cameras have little
theoretical limit in resolution since it is
sending TCP/IP data packets instead of video. Problem
is, of the dealers and integrators
interviewed, less than ten percent of the technicians
can install an IP based system on their own.
And in most cases, new cable has to be installed. Add
the fact that until recently, very few IP
camera and NVR products are interchangeable and you have
a big reason to stay clear of the
So if you look at serious video, broadcast quality of
720p and 1080i, how are they doing it? In
most cases the signal is being transmitted using HDSDI.
High Definition Serial Digital Interface.
HDSDI allows the broadcasters to send a high def real
time signal from a sideline camera, across
the field and into the production trailer at a football
game, using a single coax cable. This is a
proven method of transmission but has always been cost
prohibitive for the CCTV market.
Digital and others have recently released True HD CCTV
cameras using HDSDI signal format at prices only a
little higher than conventional cameras and DVR’s. These
systems allow the installer who knows analog to continue
doing the same installation, but the video is now true
high definition instead of NTSC.
So if the installation process does not change;
manufacturing cost is similar to analog; the picture
quality is many times that of D1, hard drives prices are
no longer an issue and capacities are
Upgrade CCTV to current standards
An average 48 camera grocery store CCTV
system utilizes over 4 miles of coax cable. Cable of
this type in an indoor environment will last for 20
years or more, so there should be no reason to re-wire a
store unless locations are drastically moved. What most
LPM’s don’t know is that if your store is wired with
coax cable, you are already wired for High Definition
Read more here ....
CCTV Enters Mainstream
first time ever, a US governing body has issued
certification on an HDSDI based CCTV system. High
Definition Serial Digital Interface, or HDSDI is the
video transmission standard utilized by the Broadcast
Industry. One of the most attractive characteristics of
CCTV systems based on the HD SDI standard is the ability
to stream 30 fps in full HD to the DVR for recording. SG
Digital presented the HD DVR / camera solution to an
integrator who specializes in the smaller casinos in the
Midwest. Based on the performance and playback quality,
they were able to install a 4-camera system with each
camera viewing one gaming table for a test / demo...Read
So Long Analog Video
So you’ve been a Closed Circuit TV provider for years
and have watched as surrounding
technologies have become better and better. We have seen
DVR’s become more powerful, and
less expensive, but with the very best analog cameras
using composite video, the picture quality has just
reached its limit.
Read more here....