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Reports and articles detailing the numerous advances being made in CCD imaging technology have tended to concentrate on developments relating to high-end colour cameras and systems, but there have been some equally significant improvements to humbler monochrome cameras, which after all still form the backbone of the video surveillance industry.


Most of the development work has centred on making these cameras smaller, with better low-light performance, increased flexibility and facilities, moreover higher levels of component integration has resulted in improved reliability, and lower prices. The HTC-383 CCD camera, which is  imported by Direct CCTV Ltd, neatly illustrates virtually all of these points.


The HTC-383 is an exceptionally compact design, the black extruded alloy case measures just 138 x 46 x 40mm, with an all up weight of just 379 grams (without a lens attached), and judging by the amount of empty space inside it could have been even smaller than that! The 1/3-inch CCD image sensor has a pixel count of just over 290,000 with low light performance rated at just 0.3 lux (f1.4). These impressive specifications are all the more remarkable considering the unit price is now only £90, (down from £100 in the last few weeks), or £126 with an optional Computar 4mm f1.2 non-iris lens.


The camera is DC powered though it doesnít come with a power supply as standard. Direct CCTV can supply a heavy duty 12 volt DC mains adaptor from Maplin for around £7.00, which is very good value, though it has to be said this particular module is rather large, the DC cable is only a couple of metres in length and the combination plug that fits into the back of the camera adds almost 60mm to the overall length of the camera. An AC powered version is mentioned in the instructions though Direct CCTV say they have no plans to import this model at the moment.


Inside the case there are three PCBs. The largest one which slots into rails running the length of the housing carries most of the video processing microchips, (predominantly made by Sony). The two smaller boards are bolted to the caps at either end of the case. The board at the front supports the CCD image sensor and its associated driver components; the one on the back panel incorporates sockets for video output (BNC), DC supply, the supply and control connections for an auto iris lens (standard square 4-pin), plus a miniature DIP switch for setting gamma correction (1/0.45) and enabling the cameraís electronic iris. The camera has an electronic shutter which is adjusted automatically, according to the amount of light falling on the image sensor chip; the shutter varies in speed from 1/120 to 1/10,000th of a second.


The main PCBs make extensive use of surface mounted component (SMC) technology, which saves a great deal of space, and makes the whole assembly light and extremely rugged. Although the camera isnít specifically billed as a weatherproof design it is quite well protected against the elements, there are no ventilation slots or holes that would allow moisture and dirt to get inside. The importer claims to have accidentally dropped one sample from a height of almost two metres without damage, we didnít replicate that particular test but it certainly looks as though it has been built to survive in a harsh environment.


Both end caps are made from a lightweight cast alloy; the one at the front has an integrated mounting bracket with a standard 1/4-inch thread, in addition to the CS lens mounting collar. Rotating the collar gives a small amount of fore and aft adjustment, for setting back-focus. Once aligned the collar is held in position by tightening a grub screw in the base of the cap. An Allen key is supplied for this purpose, along with a screw-in C-mount adaptor ring and an auto-iris plug. The accessory pack also contains a second external mounting block; this attaches to two threaded holes on the top of the case, using a pair of supplied bolts.


Apart from the two DIP switches on the back there are no external adjustments. The very brief instructions make no mention of gamma correction and simply recommend the electronic iris should be switched on, or an auto iris fitted, if the scene illumination is likely to vary throughout the day, or if the camera is going to have to cope with scenes that experience sudden extremes of illumination  (car headlights etc.). Advice for installers is scant, there are some basic guidelines for adjusting the lens, not subjecting the camera to vibration, shock or extremes of temperature etc., but after that itís left pretty much up to the installers common sense.



The low light figure of 0.3 lux, quoted in the manufacturers specifications, is in line with the results obtained under test conditions. So too is the horizontal resolution of 380 lines, though this does depend on the use of a good quality lens; the optional 4mm lens is best suited to fairly undemanding situations. Picture noise levels are commendably low, even in quite poor light. Although the automatic exposure system is quite basic, it can compensate for a reasonably broad range of lighting conditions. It responds fairly slowly to rapid changes in lighting level though, and care needs to be taken during installation and alignment to avoid bright lights within the image area or strong backlighting, otherwise the electronic iris tends to over-react and the image can be washed out.



The automatic iris and exposure system is relatively unsophisticated, compared with whatís now appearing on middle and top range cameras, though itís perfectly capable of dealing with most routine situations. The  383ís low light capability and resolution figures are not in themselves all that unusual, though this level of performance is rarely, if ever seen on cameras as small and inexpensive as this one.



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                         ****                           




R.Maybury 1995 0404












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