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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.



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...



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.



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.



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                         ***                          




Ó R.Maybury 1997 1610



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