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SONY SSC-DC50P COLOUR VIDEO CAMERA
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WHAT OUR EXPERTS SAY...
Digital signal processing circuitry has
become an increasingly familiar feature on surveillance video cameras over the
past five years. DSP systems are used in a variety of different ways, from
automatic exposure control and high-speed shuttering, to picture noise
reduction and motion detection. Digital technology has played a pivotal role in
improving the flexibility of video cameras, enabling them to operate in a much
wider range of conditions, using a broader selection of lenses, with increased
efficiency and picture quality. Digital microchips have also helped reduce the
cost, as well as the size and weight of video cameras, so when Sony launch two
new high-end colour cameras, using the latest digital signal processing
systems, it’s worth paying attention.
The two cameras in question are the SSC-DC50P
and SSC-DC54P, though apart from their power supply requirements and external
synchronisation facilities, they are virtually identical. The DC50P, which we’re
looking at here, requires a 12 volt DC supply, whereas the DC54P needs 24 volts
DC. Image sensing is handled by a 0.5-inch interline CCD with 752 x 582 pixel
array. This has a low light sensitivity down to 1.9 lux, the quoted resolution
is 470-lines. The camera is housed in a steel and die-cast alloy case, with a
plastic moulding on the back panel. The
main external features are a large thumbwheel, that protrudes through slots in
the top and bottom of the case. This is the flange-back or back-focus
adjustment, designed to accommodate C or CS type lenses. On the right side of
the camera body is a standard 4-pin plug for an auto-iris lens (DC or video sensing
type), and a series of cut-outs, giving access to switches and presets mounted
on an internal PCB. More about that in a moment.
A mounting plate with a 1/4-inch UNC threaded
boss can be fitted to the top or bottom of the case using four small screws. On
the back panel there are two BNC sockets. The SSC-DC50 has a power multiplex
feature so that in ‘Mode A’ the BNC socket on the left carries a DC supply, video
sync in and CVBS video out, whilst the right socket also has the video output
signal. In Mode B the left socket carries video out and the right one video
sync only. On the SSC-DC54 there is no mode switching, the left-hand BNC socket
is used for composite video output, the other one is for an external synch signal.
Next to the BNC sockets there is a green power-on LED. Below that are two slide
switches. The top one is an unusual power on/off switch, the other is the mode
switch for the two BNC sockets. (the SSC-DC54 doesn’t have an on/off switch). In
the bottom left hand corner there is a mini DIN socket for Y/C (S-Video) output
and next to that is a screw terminal, for the DC power supply.
Inside the case is stuffed full of
high-density, double-sided surface-mounted PCBs. There are at least five of
them, along with various daughter boards and a screened module, for the power
supply. The standard of construction is most impressive. All of the circuit
boards are screwed to a steel chassis; it looks as solid as the proverbial
brick out-house! The flange-back adjustment is smooth and moves easily,
moreover because the thumbwheel is accessible from the top and bottom, in-situ adjustment
is not a problem. Once set it can be locked in place using a small screw on the
side. The slots in the case for the flange-back adjustment and the switches on
the side of the camera mean that the camera is very poorly protected against
the ingress of dirt, dust or moisture. This could be a serious consideration,
even in a mildly polluted atmosphere, in which case it would be advisable to
house the camera in a protective enclosure.
The control panel on the side consists of an
8-way miniature DIP switch, two rotary switches, two presets, a press button
and a slide switch. The DIP switch is responsible for AGC enable/disable,
normal or turbo AGC mode (backlight compensation on/off, shutter on/off, white
balance presets, outline sharpener on/off and sub-carrier phase adjustment
on/off. The uppermost of the two rotary switches controls shutter speed and
operation. The options are manual adjustment from 1/50th to 1/10,000th second, in
7-steps, there’s also automatic, and auto with forced backlight compensation.
The second rotary switch is for setting the
AE spot mode. This involves targeting AE functions on the whole picture, or a
designated portion. The target area is shown by a superimposed shaded
rectangle, that appears on the screen for a few seconds when the adjustment is
being carried out. The settings are whole screen, one of 7 positions (centre
small, left down, right down, lower centre, left up, right up, centre big), forced
backlight compensation, or excessive forced backlight compensation.
The remaining controls include a switch for
auto iris mode (video or DC), two potentiometers for phase and sub-carrier
phase adjustment, and a recessed button for setting auto white balance lock.
OPERATION
Mounting and the initial set-up should pose
no problems for experienced installers; those with a greater dependence on
instruction manuals may find the Sony paperwork quite hard going. The
information is mostly there, the trouble is trying to find the relevant bit, on
a large fold-out sheet, the size of a broadsheet newspaper, with the text repeated
across both sides in French and Spanish. Fortunately there are some helpful diagrams, showing the most
common configurations.
Most of the pre-installation procedures are
reasonably straightforward, and once the camera is in place the side mounted
controls are fairy accessible, though trying to set the microscopic dip switches
in a confined space could prove interesting...
PERFORMANCE
Resolution is as advertised, but that’s only
part of the story. What makes the image really stand out from the crowd is the
unusually low noise levels. The SSC-DC50P produces one of the cleanest,
crispest pictures we’ve seen, even on a CVBS feed. It’s sharper still on a Y/C
connection. Some noise is to be expected, especially on and around heavily
saturated colours, but the Sony camera rarely misses a beat. The camera has a
good range of exposure facilities, and the basic AGC and electronic shutter can
handle most routine lighting conditions -- including sudden changes in level. The
AE Spot facility should be able to take care of any awkward bright lights
within the scene area, the backlight compensation modes work very well indeed.
Together these features means that in a lot of situations, more expensive auto
iris lenses will be unnecessary. Colour accuracy is excellent, even in
difficult mixed light. The auto white balance system is able to deal with
almost any combination or type of lighting and the auto tracing modes cope well
with changes.
OVERALL ASSESSMENT
Build quality is excellent though we’re
slightly concerned about the unprotected slots on the side, for the set-up
controls. This really could do with some sort of cover. A thin film of dust had
built up inside the camera after only a few days of exposure to the atmosphere of
a typical office environment. It’s tempting to cover the holes with a strip of
tape, though this isn’t a particularly elegant solution moreover it might have
implications for cooling. Nevertheless, the camera turns in a most impressive
set of results, and it is definitely worth shortlisting for installations where
image quality and the ability to handle significant changes in scene lighting,
are a priority.
PRODUCT ASSESSMENT
Design and design features ****
Circuitry and components *****
Ease of installation and wiring ****
Range and variety of functions ****
Accompanying instructions ****
Technical advice and backup ****
Value for money ***
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Ó R.Maybury 1997 1610
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