High Definition CCTV Information

view in PDF    

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
technology.
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.
Until now.
GraphSG 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
enormous….
WHY WOULD ANYONE STAY WITH ANALOG?
Cabling issue with HD Cameras ---- There is no cabling issue.
With the introduction of the HDCCTV cameras, there has been a large resistance in the area of
cabling. As the country’s leading expert in HD installations, here are some realities.
1) HD Cameras can use existing RG-59 CCTV cable reliably up to 300 ft. This means direct
replacement of Camera and DVR up to 300 ft is no problem. Now, consider all of the applications
with wire runs under 300 ft. Our survey’s show that it is actually the majority of the installs taking
place today.
2) How many times does a dealer replace a camera system on an upgrade and leave the
existing cable in place. VERY RARELY. Even in national retail chains, every time there is a
remodel or a retro fit, they rewire the store.
3) Your cable costs is now half of what it was. In the old days, we used to pull RG6 for
“high end” cable applications. With the rising cost of copper a few years ago, RG6 is now about
one half of the cost of traditional 95% copper RG59. An HD CCTV Camera reaches its full
capacity over conventional RG6, allowing distances of well over 800ft.
4) You were going to rewire anyway. If you convinced your customer to go to IP cameras
because you sold him on better quality, guess what. You are going to most likely rewire the site
with CAT 6 anyway. Why not use RG6 and have a much higher performance system than IP can
deliver.
By the way, what is the cable distance limitation for an IP camera on CAT6? 300ft!
We have boosters, splitters, quad processors, DVR’s, fiber transmitters, IP converters and
anything else a system could require to offer your customers Broadcast quality video.