Specifications

Security 2009
KNOW-HOW: Camera Technology
S38
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Today, current camera technology allows surveillance applications
which previously would have only been possible by applying very ex-
pensive special cameras.
Many different camera models and versions are available for
versatile applications.
The range of products include camera mod-
ules for concealed mounting, compact cameras, system cameras, and
high-speed dome cameras.
The type of camera to be selected depends on the range of appli-
cation.
The cameras which are shown in this catalogue can be divided into
different camera classes.
Module cameras
The module cameras are also called board cameras or PCB cameras
and are generally supplied without a housing or only with protection
against accidental contact and short connection cable. These types of
cameras are generally intended for concealed or subsequent mount-
ing in their own housings. Only small openings in front of the lenses are
required to have a good visibility. In some cases, for module cameras
with pinhole lenses an opening of 2mm diameter is sufficient.
At basic modules with lenses with a thread diameter of 12mm, it is
possible to replace those with other focal lengths.
Compact cameras
This group includes cameras which are completely ready for oper-
ation. They usually feature replaceable lenses, but are already in-
stalled into a housing and therefore ready for operation. They are
available in various designs. Cameras with one-cable technology are
very popular in this case, particularly cameras in outdoor housings,
e.g. the TVCCD-160S series from MONACOR INTERNATIONAL.
Cameras in types of housings which can hardly be identified as cam-
eras (e.g. disguised as motion detectors or smoke alarms) are also in-
cluded in this group.
With compact cameras, applications of basic up to medium re-
quirements can be met at a favourable price. For merely checking
whether there are persons in certain areas, the features and resolution
are sufficient.
System cameras
The system cameras are the classic type of camera technology. Due to
the standard CS or C mount thread, these cameras can be combined
with numerous lenses which are never supplied with the camera. Only
thus it is possible to select the perfect picture detail. These cameras can
be adapted to the application up to a high degree due to versatile
types and their different features. The kind of application ranges from
standard applications to applications of high requirements.
Speed dome cameras
High-speed dome cameras are the racing machines among the cam-
eras, so to speak.
On the one hand, they consist of a high-quality camera with motor-
zoom lens and on the other hand, they feature a mechanism for quick
panning and tilting. Movements of several hundred degrees per
second are
carried out, i.e. a complete 360° turn is done in less than
1.5 seconds. A standard pan/tilt head takes approx. 60 seconds for
the same task.
The automatic focus of the camera provides a clear picture at all
times.
Presets allow a quick access to stored positions. In this case, the cam-
era is moved automatically in a horizontal and a vertical direction and
the zoom is set automatically to the stored focal length. The automatic
focus provides a clear picture.
To control a high-speed dome camera, a control unit is always re-
quired. This can be an independent control unit. The latest units for
picture storing and transmission can also control this type of camera.
Despite the parallel connection, the supplied interface (RS-485) pro-
vides an independent control due to its bus concept.
Network cameras
This latest class of cameras features a totally different connection to
customary CCTV cameras. Network cameras are a combination of
video webserver and CCTV camera.
The signal transmission to the monitor is not done via a separate
coaxial cable. The signals are split up in electronic data packages and
then transmitted within a network via the TCP/IP.
Besides the BNC output, this type of camera additionally features a
direct connection for a computer network.
The advantage of this camera class is that no new cables have to be
laid, but the existing computer network can be used instead. Each con-
nected computer can access the pictures. For this purpose, the
computer
must at least have an Internet browser as a basis. Further
features, like e.g. recording on any desired computer can be realised
via special additional programmes. In future there will be many new
products in this field.
Additional types of cameras
More and more features are integrated into the camera. Thus, cameras
with built-in motorzoom lenses or with integrated wireless video trans-
mitters are already available.
Important notes concerning the choice of camera
Resolution
An image sensor is built up of individual pixels which are located in a
grid side by side and on top of one another.
A video picture consists of 625 lines according to present stand-
ards. This results in a visible resolution of approx. 580 pixels vertically
and approx. 760 pixels horizontally. These values are determined by
TV standards and cannot be compared with values of the digital
photography where the picture format is unlimited. If the picture is too
large, it is scrolled.
The vertical resolution is almost the same with approx. 580 pixels at
most cameras. The high-resolution camera is able to represent approx.
760 pixels in horizontal direction and the standard camera approx.
500 pixels. Slight deviations of e.g. 20 pixels can hardly be noticed.
While the maximum number of pixels can clearly be demonstrat ed,
the indication of the resolution does not really seem to be very
reasonable.
The resolution is defined as the quantity of vertical lines
which can still be resolved by the camera. The resolution is not only de-
termined by the CCD chip but also by the integrated signal processing.
The better the signal processing, the higher the resolution.
Camera Technology