2010 a cctv oddity

There have been enormous changes in the types of technology, products and systems being used in CCTV systems over the past decade, so much so that one wonders where the next 10 years will lead us. With a bit of experienced guesstimation it may be possible to predict the types of products we will be using in ten years time – in which case it may not come as quite such a shock!

Whatever types of systems there are, they will be sure to use the same basic components: fixed cameras, movable cameras, lenses, monitors, recorders and switching and control systems.

Costs in real terms of basic cameras will continue their downward spiral. Perhaps by 2010 this will have changed basic prices enough so that mass adoption in the domestic market becomes possible. However this article is concerned with the professional CCTV market so we'll leave that one there.

Premium prices

In the camera market dual-format (colour and monochrome cameras) are currently the vogue. Comparatively few manufacturers are producing these and so premium prices are being charged. These bonus profits are bound to attract other manufacturers into the market and so by 2010 dual-format cameras may become the standard in the same way that colour cameras are now in the UK.

Consequently with a large number of relatively similar products around, price competition will be fierce and manufacturers will be looking to offer something different to command a premium price once more.

But from where will they get the difference? It is likely that manufacturers may seek to make different cameras by further improving picture quality by using, for example the multi-CCD technology currently being used in broadcast camcorders. This prospect is very attractive.

Who will specify a colour camera with 460 TVL resolution against one with 700 TVL? (Whether they really need to is another matter, but that has never bothered our industry). There are limits, though. A good part of broadcast TV quality comes from excellent lighting and this is not normally available in a railway station car park on a wet December evening!

A likely alternative is the use of network or structured wiring systems technologies inside the cameras themselves, allowing the direct connection of twisted pair cables to the cameras rather than use of coaxial cable, making savings in cable and connector costs. This is certainly most likely. As the size of dual-format, DSP camera modules falls there will be space freed up inside the camera casing to mount the Balun (balanced/unbalanced transformer) inside the case and have screw terminals on the back of the camera rather than a BNC.

The only fly in the ointment is that if conventional monitors, switchers etc are being used with cameras of that type then the cameras will need a second Balun 'in the box' to allow them to plug into the BNC on the monitor or whatever.

In fact, after 10 years camera manufacturers may have taken this a stage further by including video compression inside the camera itself and making them directly connectable to an Ethernet network and accessible by a TCP/IP number which will replace the camera number. There are already one or two manufacturers doing this.

It is still early days for the technology and a number of problems remain to be solved. One of these is recording. If we want to time-lapse record all the cameras in the system, as is popular now, all the cameras will need to be transmitting pictures across the network all the time … a prospect which will fill most IT managers with nothing short of unmitigated horror. Consequently CCTV may well stay on its own 'network'.

Continued reduction in the price of thermal imaging cameras may well lead to their replacement of monochrome cameras for low light applications. This is certainly attractive for high security sites as TI cameras can see through fog and smoke!

Time for a mini PTZ

Continued size and cost reduction in dome cameras plus improvement in quality will probably make domes the de-facto choice in indoor installations. However, limitations due to optical distortion and problems of cleaning of small diameter globes limit their use in outdoor locations. So will we be still be seeing big clunky PTZ next decade? Probably not.

No-one seems to have caught on at the moment that reduction in camera/optics package size means an overall smaller housing can be used which means less total weight. Consequently the PTZ itself can be made smaller with faster, less powerful DC motors and yet still approach the speeds of domes. The entire assembly of housing/PTZ can be a single unit allowing the use of different cameras and telemetry systems, but still giving good zoom picture quality by using plain glass or Lexan in front of the camera.

Such camera/PTZs already exist in early form for indoor use. I'm sure that by 2010 someone (maybe after reading this article!) will be making and selling truckloads of outdoor housing/PTZs which are four times smaller and four times faster than those we currently use.

1/8 inch lenses - and beyond?

It is unlikely that the trend to reduce sensor formats that we have seen over the last 10 years (from 2/3 to ¼ in) can be sustained. As focal length gets smaller it becomes increasingly difficult to grind lenses that produce good picture quality. We all know the difference in picture quality that you get from a disposable 'fun' camera and a good 35 mm SLR camera, using the same film.

Similarly, we all know the type of picture distortion you can expect from a pin-hole lens. Perhaps in ten years lens makers will emphasise promoting larger, multi-coated lenses which give outstanding picture quality.

There is also the concept of putting a lens in front of the CCD or even individual pixels. However huge materials problems remain to be overcome for lenses which will have no zoom capability.

Feeling a little flat?

2010 will see the probable end of use of CRT-based CCTV monitors (apart from very small installations) due to the continued low price of domestic TVs with video inputs via SCART. Tremendous strides have already been made in availability and reduction of cost of flat plasma screens, fuelled by the laptop PC marketplace.

This technology will have conquered CCTV monitors by 2010, probably being used in the same way too. By 2010 your digitally recording multiplexer may well have a 14 inch colour plasma screen on top, which will fold down flat out of the way when you don't need it to review recordings.

It is also likely that monitor makers will include additional items inside the monitor to make unique products for which premium prices can be charged, such as network connection so that it is much easier to provide monitors in different places round large locations. You will simply plug the monitor in the network to be able to view CCTV.

Goodbye ½ inch VHS tape

Digital recording is now really starting to come of age. Hard disk capacities are rising and costs falling every six to eight weeks. Also new removable digital recording media technologies are emerging. The CCTV market now has the first few real credible alternatives to VHS VCR with similar looking devices that can store a month's worth of high quality video on-line without the need for tapes.

These digital recorders come with many other features including remote viewing and control, video motion detection, data recording as well as video and audio recording. By 2010 these will have become the exception rather than the norm and VHS tape recorders will have completely disappeared from our industry, apart from some servicing of old machines.

For multi-camera recording systems, multiplexers are now a very mature product. There are many makes with very little to choose between them and consequently price competition is fierce. Already manufacturers are starting to forward integrate into the recording units themselves. So by 2010 we may see standard video recorders for one, four, nine, 16 and 32 cameras with multiplexing added in for very little additional cost.

In fact as camera prices fall we may see the popularity of single channel recorders fall and four, nine, and 16-camera models may well dominate the video recorder market. The other side of the coin is that individual multiplexers may have become mostly obsolete.

The big switch

I have left switching and transmission systems to last, as possibly the biggest and most important sea-change affecting our industry. We already have cameras with very advanced DSP (digital signal processing) circuitry, which allows those cameras to produce outstanding pictures (with the right lens and lighting, of course). We also have digital recorders that can record and reproduce that same quality.

However, in between the two is good, old-fashioned analogue technology … 75 Ohm composite video cables. The big change our industry is likely to make by 2010 is the change to totally digital systems, where images are captured, transferred and recorded digitally. This promises all sorts of exciting possibilities.

One of these is that of error correction. Using this, extra "check bytes" are transmitted, along with the video signal and if any noise or errors occur (within limits) when the video arrives at its destination these check bytes are used to correct the errors and restore the picture to its original high quality.

However, a number of issues will need to be resolved over the next decade if we are to reap the benefits of totally digital systems. The biggest issue is that of the standard of video signal and transmission which will be used. The composite CCIR monochrome and PAL colour formats we use now were set for us by the broadcast TV industry (the same is true in the USA with EIA and NTSC).

It is an extremely strong possibility that the same will be true in our switch to totally digital and it will be the standards used in broadcast digital TV, such as D2 and CCIR Rec.601/Rec 658 that may be adopted in closed circuit television systems.

A secondary but no less important issue is that of bandwidth. We currently use a bandwidth of six MHz (DC to six million cycles per second) to send a good quality PAL colour CCTV signal from the camera to a monitor, recorder or whatever.

The equivalent digital broadcast video signal would need 60MHz of bandwidth and need some very special techniques in sending these signals from one place to another. It would be a struggle for our industry to cope with this change as many people still manage to get current coax cable systems wrong and would much rather install twisted pair!

The answer may come from the networking and structured wiring systems market where 100MHz backbone systems are now common. Products and techniques from structured wiring may be prevalent in our industry by 2010.

The alternative is to put digital video compression inside each camera and send pictures digitally after compression. Ten to one compression reduces video picture digital file size by ten times but without reducing digital picture quality significantly. Ten to one compression also reduces transmission speed data by ten times too, from 60 MHz back to six MHz again. This would allow existing cable to be used with new digital cameras. So by 2010 a whole new family of high quality DSP "wavelet" cameras may well be in common use.

Once the change to digital transmission is made, switching systems will change too, as a little desktop switcher simply won't work. Currently all large matrix manufacturers use composite video inputs and outputs. New ranges of matrix switchers, which can switch new digital signals, will appear. The alternative will be cameras, which send pictures digitally using computer network protocols.

Whatever happens, the next ten years are likely to be just as dramatic and exciting as the past ten. It will be interesting to look at this in 2010 and see if we have really moved in these directions, before writing another article for 2020!