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SONY SSC-C158P COLOUR VIDEO CAMERA
COPY
By any measure the Sony SSC-158 is a fairly
conventional compact colour camera though it is notable for being their first
camera to use a 1/3-inch CCD imaging chip. The chip in question is a
high-performance Hyper-HAD type with a matrix of 291k pixels. A feature of this
design is a microscopic on-chip lens (OCL) array, this improves the sensor’s
light gathering characteristics and contributes to a low-light sensitivity of
less than 2-lux (f/1.2), though Sony confidently claim it will still produce a
useable image down to 1-lux. The Sony SSC-C158 is pitched at the busiest
segments of the surveillance market. It’s primary role is in single camera
set-ups, though it can be easily integrated into suitably-equipped multi-camera
systems.
Installation and alignment have been made as
effortless as possible; it has a fully automatic ‘CCD Iris’ exposure system,
based around an electronic high-speed shutter that varies between 1/50th and
1/100,000th of a second, according to the amount of light reaching the sensor
chip. It has fixed or auto-tracing white balance, chosen to suite scene
lighting conditions, more about that in a moment. The camera is powered by a
built-in mains power supply; Sony have produced a low-voltage, externally
powered variant (24 volt AC, Class 2), called the SSC-C154, though this is
currently only available as an NTSC model.
Flexibility is always an important
consideration and the C158 can be used with C or CS-mount lenses with manual or
auto-iris (DC drive type). The video output is a standard 1.0V p-p PAL signal,
with a variable V-phase adjustment for integration with multi-camera systems.
It doesn’t come with any mounting hardware, that’s left to the installer, but
the mounting plate (1/4in UNC), can be fitted to the top or bottom of the
casing.
The camera is housed in a tough steel case,
with ABS plastic end caps, no attempt has been made to weatherproof the casing,
a protective housing is required if the camera is to be used in a damp or dusty
environment. Internal construction is very simple, all of the main components
and assemblies mounted on a pressed steel chassis, so it should prove quite
rugged. Most of the electronics are contained on a single, double-sided
glass-fibre PCB, the circuit board has a high proportion of surface-mount
components which will ensure a high degree of reliability and immunity to
physical shock. The mains supply is built inside a separate plastic box; it’s a
switched-mode design, and although more complex than a normal transformer type
PSU, it’s more efficient, and generates less heat, another hopeful sign for a
long and healthy life. Overall it shouldn’t present installers with any
problems.
Controls are few and far between. Most of
them are grouped on the back panel where there are two miniature slide
switches, one for switching the auto iris on and off, the other for selecting
auto (fixed) or auto-tracing white balance. In addition there’s a push-button
for locking the auto white balance setting, and two recessed buttons for
adjusting V-phase. Also on the back panel is a BNC socket carrying the video
output, and a captive mains lead, which emerges just below the video output
socket. The cable supplied is approximately 1.5 metres long. A 4-pin socket for
the auto iris lens is on the left side of the camera, close to the front, along
with the incident light control and lens mount screws.
Initial adjustments are confined to selecting
C or CS mount, according to the type of lens being used. This doubles up as the
back-focus adjustment, once set it is locked into position with a grub screw.
If the camera is being used with an auto-iris lens it may be necessary to use
the light level (L/H) control to compensate for incident lighting. The L/H
control is accessed through a hole in the side of the case, though it may not
be necessary, the instructions say the default setting should be suitable for
most situations.
The camera’s white balance system has two
operating modes. The AWB (auto white balance) setting is used when the lighting
conditions do not vary to any significant extent; to lock the WB setting the
camera must be pointed at a plain white surface, the lock button is pressed and
the setting is memorised, after the camera has been switched off, then back on
again. In the ATW (automatic tracing white-balance) mode the camera adjusts the
white balance continuously, to suit the prevailing conditions; manual setting
is unnecessary.
PERFORMANCE
The specifications claim a horizontal
resolution of 330-lines, this was confirmed by our tests which suggest that
under ideal conditions it may even be slightly better than that. Sony quote a
low light sensitivity figure of 1.9-lux, and once again this is on the
conservative side, though at these extreme levels the image is very grainy but
still able to yield useful detail. The auto exposure system is reasonably
effective but fairly slow to respond to sudden changes in lighting level. In
some circumstances this can be an advantage, though Sony appear to have
employed a fairly basic metering system which isn’t particularly discriminating
and doesn’t cope especially well with scenes that contain one or more bright
light sources. Colour accuracy is good, even under normally troublesome
fluorescent lighting. The instructions warn that colour changes can occur when
the CCD Iris function is enabled, though we didn’t notice any problems during
our tests. The CCD sensor on our sample had at least one faulty pixel/pixel
group, with a bright spot permanently visible towards the lower edge of the
screen.
OVERALL ASSESSMENT
The C158’s automatic systems are capable of
dealing with most routine lighting situations. Installation is quick and
simple, the standard of construction is very high, and maintenance demands are
low. Sony have wisely judged the need for a sensibly priced, no-frills colour
camera that has good low-light performance -- the SS-C158 ably meets that need.
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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© R.Maybury 1994 0711
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