Is it better to use a
monitor or a television?
LCD or cathode ray tube?
(A beginners’ guide)
All DSE cameras can be connected to a normal television set
and deliver excellent quality images. Viewing on
a
television is a good value for money solution: in view of market volumes you can
buy large, high quality televisions relatively cheaply, either with cathode ray
technology or LCD. To view the images on a television screen all you need to do
is connect the audio/video cable from the camera (if it is a hard-wired camera),
or the RadioEye® receiver (if it is wireless) to the AV socket on the television
as shown here. (You will need to use a SCART/RCA adaptor if your TV only has a
SCART socket). The TV can also be connected in the same way to the video outputs
from quads, multiplexers and switchers.
The drawbacks of televisions and the
advantages of monitors
A professional CCTV monitor, however, is very different from a common
television set. The most important difference lies in resolution. If you buy a
camera with a resolution of 380 lines for instance, you should view it using a
monitor of that resolution or higher, otherwise the quality of the camera will
be penalized by the monitor. A commercial television set provides 300 TV lines,
while DSE monitors reach up to 1000 lines, guaranteeing perfect fidelity, even
with the very best cameras. In the tutorials section there is an area dedicated
to choosing the right
resolution, which explores this subject. There is also a
tutorial on monitor technology.
Two other good reasons for choosing a specific CCTV monitor are reliability
and life-span. DSE monitors are in fact designed to function 24/7, while
televisions are usually manufactured with a daily use of around 8
hours in mind, with frequent periods to cool. A television
subjected to uninterrupted use will not usually last long.
Lastly remember that televisions are often bulky, awkwardly-shaped items, while
CCTV monitors are specifically designed for ease of use when teamed with other
monitors or rack-mounted. They also come in a metal container which ensures that
especially in harsh conditions, they are more durable than the flimsy plastic
used for commercial TVs.
Flat screen and traditional cathode ray tube
Flat screen monitors (TFT/LCD), which were only used with computers until a
few years ago, are now relatively common in CCTV systems. Compared to a
traditional cathode ray tube (CRT) monitor they occupy less room, are easy to
install, whether wall-mounted or rack-mounted, and thanks to the anti-reflection
flat screen and high level of luminosity, are easy to view in all light
conditions. Moreover, they do not use a lot of energy and heat up very little.
Traditional CRT monitors still have a few advantages compared to flat screen
monitors. They usually offer higher image and colour fidelity, with faster
refresh times when it comes to moving objects and a wider viewing angle than
most LCD monitors. From the cost point of view a CRT monitor for CCTV is usually
cheaper than an LCD monitor of the same size.
