Cooperman

Welcome back Metz, Any plans to visit London? .... anyone??

Over here, we call them "installation engineers" .... amongst other things!

No AK's on this side of the pond (unless you happen to be a yardie). Even the Police don't carry guns, unless of course they are in specialist units. Just another average day in Old London Town

Hey rory, The main problem over here is lack of knowledge. It's not unusual for some very reasonable equipment to be set up badly, and then it's a complete waste of money. Lots of 'installers' can plug the bits togethor, but they don't really know how to use it properly. Very depressing!! Unless the security services are getting assistance we don't know about, the very many hundreds of CCTV cameras used for vehicle plate recognition as part of our 'Congestion Charge ' scheme, actually stop recording beteen 6.30 p.m. and 7.00 a.m. Now that's useful. Incidentally, if you want to drive into Central London, it's roughly the equivalent of US$ 13.00 per day to enter the zone, and then US$ 5 per hour to park.

Four and a quarter million CCTV cameras in the U.K., and the vast majority are not actually set up properly The only pictures of the bombers released so far, are'nt all that good (what a surprise). The most recent news reports state that 6,000 videocassettes have been seized by the Police, with some suggestions that this could eventually increase to perhaps 25,000, and yet not one word has been said about reviewing any DVR recorded material. I would imagine it's a bit of a race against time to retrieve any DVR material before it's wiped off. And that's just the good news

My deepest condolences to you and your family dusan.

Just to clarify, the 5mm spacer ring is only used on 'C' mount lenses, when they are fitted onto 'CS' mount cameras. If you are using a CS mount lens on a CS mount camera, then you won't need the ring. Those 2 varifocals you mentioned G22, the Fujinon is a 1/3" format, and I'm guessing the much larger 3.8 - 8mm may possible be a 1/2", in which case it would probably work better (optically) on your 1/3" camera. I agree with VST_Man that if you don't need a varifocal, you would be better off with a fixed focal length lens.

Nice job rory Agree with Data about using fibre points (nodes) and then using copper to individual cameras (arranged as groups of perhaps 6 cameras per node). A couple of points to have a think about; for every 150 metres ( yards) or so perhaps allow 5 metres of looped fibre to be hidden away. If after installation the cable gets damaged, you've then less of a problem pulling the bits togethor to effect a repair. Have a think about whether you are going to be able to repair cables if they are damaged. Doing field repairs on fibre is a lot more challenging, than repairing copper. And make sure whoever is pulling the fibre a] knows what they are doing, and b] is prepared to accept responsibility for what they are doing! If they break the fibres, they will have to put it right!

Agree VST_Man that normal heat shrink sleeving won't seal any joints. However, I have used 'hot melt' adhesive lined sleeving in the past (you can have any colour you want, so long as it's black), and that will live quite happily underwater, provided it's done correctly. Where in line BNC connectors are being sealed, the plugs (or sockets each have a couple of inches (about 5 cms.) of 12mm adhesive lined sleeve shrunk over the back end of them to bond with the cable, and then 16mm is shrunk over the complete length to provide a tough sealed outer tube. I can't say how long it will last, but so far, I think twelve years and counting is about the longest

Quite right cctvfan, Just to clarify one point though, Most manufacturers incorrectly use 25x to imply the zoom ratio of the lens. In practice, 25:1 is the correct way to display a zoom ratio (i.e. longest to shortest focal length), and 25x would normally imply 25 times magnification, when compared to a normal standard focal length lens. So for example, an 8 - 120 mm zoom is a 15:1 optic, which provides a maximum magnification of 10x on 1/2", and 15x on 1/3".

O.K. guys, if a stressed out Brit was thinking of heading Stateside at the end of the year, what would you recommend, California or Florida?

I don't think paranoid has posted for a few months; he's based somewhere in North London (that helps narrow him down to one of five million of us!!!). Hopefully he's o.k., but I've no idea how to get in touch. Latest news is that the bombers have all been described as 'suicide bombers', with three based in Leeds which is in the north of England. It has been suggested by a former Commissioner of the Metropolitan Police (the main London force) that there could be a couple of thousand individuals living in the U.K. that have previously been through the training camps in Afghanistan. Now that is what you call 'food for thought' !!!!

Cheers for that Herm!

Haven't heard anything about Manchester, but parts of Birmingham (the U.K.'s 2nd largest city) have been sealed off and evacuated in response to specific intelligence concerning a threat. I just drove past the Hard Rock Cafe in Piccadilly, and that's gone up in smoke! If anyones interested in some very well done, but slightly water damaged burgers and fries....

I'm not sure where this 1/2 million camera figure came from; the latest estimates for CCTV cameras in the U.K. is actually around 4.25 million, which for better or worse makes us the CCTV capital of the world. In practice, London has the highest saturation of cameras anywhere in the country, and that in part reflects the fact that the city has been on the receiving end of terrorist attacks for over thirty years. For those not familier with the geography, the "City of London" (which is the financial heart of the country) is actually a relatively small area of (Greater London) about one square mile on the north side of the river Thames. As the City of London was a favoured target for Irish republican terrorists some years back, it is actually comprehensively covered by CCTV, with both traffic and security camera networks covering a significant proportion of the area. However, the areas outside of the City, particularly the West End where all the major shops and theatres are located, is not so well covered. I drove through this morning and it was interesting to note that the square where the American Embassy is situated, has now been completely closed to traffic. At the moment, apart from the areas immediately surrounding the crime scenes, the rest of London is 'business as usual'. This may be the worst terrorist outrage ever committed in the U.K., but it just makes us more resolute to carry on regardless. On behalf of all the Brits, thanks again guys for all your kind words.

What can I say?

Cheers for that rory, The news report just said the Police are involved in the biggest CCTV search ever (they describe the task as "daunting").... quelle surpris!

keith, It's a few years since I last played with Fibre Optic gear, but one of the standard 'cost cutting' techniques, was to use one fibre to transmit a multiplexed display (i.e. your 8 cameras) and a second fibre for individual channel selection. Now if you have a single two channel (i.e. two video input) multimode transmitter, you can pump both signals down the one fibre. If you increase the number of channels per fibre, then the cost tends to increase alarmingly on fibre equipment, and you also risk putting too many eggs in one basket. In the past, I often tended to use quad (four fibre) cables, which at that time were not that much more expensive than pair cables. If you wanted to use low cost single channel fibre transmitters, you could use one 'pair' for video and reverse telemetry (RS 485), and a second pair for an additional video channel with one redundant fibre. Even from your basic schematic, there are many options open to you, and it would probably require a lot more information (not least the length of cable runs) to determine what is your best option.

1993 in London really was another world! If you were here now, most of the buildings look the same, but I doubt you'd recognise the place. We had less than 24 hours when the town went absolutely loopy over the Olympic success, and now emotions have swung completely in the opposite direction. Here's to a peaceful weekend!

Ain't that the truth

Agree with you 100% rory, if you set a camera up on a bench it should work anywhere (it may possibly need to have the exposure control adjusted slightly if it's an auto iris lens). 100 feet in the Bahamas is the same as 100 feet in London or anywhere else for that matter. In the past I've focussed cameras out the window, and then sent them off to Africa (with my fingers crossed ). sjmaye, you're out of focus, that's the bottom line. Do as rory suggested on refocussing the camera. Do it as late as possible, with the iris wide open (twist the 'Level' pot with a small trimmer or screwdriver to open the iris before adjusting the focus, then turn the level back to close the iris to it's correct setting). Personally, I would love to have known how you would have got on with the Manual Iris lens I originally suggested. If you are ever up for trying it, estimate the focal length you've set with the varifocal, and then buy an equivalent fixed focal length manual iris lens (preferably Pentax) and fit it with the "Electronic Iris" fucntion switched on, and the iris closed to f4 (after you've focussed at maximum aperture). You appear to have bucket loads of light available, so I would be very surprised if you couldn't use a manual iris lens to much better effect.

It's not that unusual to find 'dead' pixel numbers increase as imagers become older. I happened to test out a seven year old camera recently, and that had about half a dozen failed pixels, when previously there were none.

So what's 'M' rory ... massive truck? ANPR systems are actually quite common over here, the biggest being the network of London Congestion Charge cameras (about 800 from memory). The main problems we have are not connected with the technology, which is now proven at 90+% reliability. There are increasing numbers of vehicles driving around with "cloned" registration plates, and certainly in central London, a noticeable percentage of foreign plates which the software is simply not programmed to read.

Thanks for that rory, The vast majority of systems installed on the London Underground have in recent years been upgraded to digital, with I believe certain 'lines' going over to centralised recording at network control rooms. Video images are regularly released to the press and media as part of criminal investigations, and quite honestly they are an absolute joke. CCTV images showing blob A pushing blob B onto the tracks ... you get the picture (sorry!) From memory, the station normally used by Mrs. C. has about 15 cameras in a booking hall, no more than about thirty feet (10 metres) in diameter - and guess what; wrong location, wrong height, wrong lenses, and that's just what I can see from standing and looking at them!! Nothing has yet been mentioned about the bus, but as a fairly new vehicle in the fleet, it would almost certainly have been equipped with a number of minidomes, and a mobile DVR. As the driver survived the explosion (the device was located towards the back of the bus on the upper deck), it would appear quite possible that the DVR may have been shielded from any effects of the blast by the driver himself. The down side is that again, whenever images have been released to the public (which has happened numerous times in recent months), the quality has been about two grades above total rubbish.

Thanks for all your concern guys! Just as an update, the latest figures suggest around 50 fatalaties (expected to rise), and over 700 injured (some critically). The authorities do not believe that any of the four attacks were suicide bombers (although at a guess, there is the possibility that the bus bomber didn't reach their intended target before the timer detonated the device, but that theory is somewhat speculative). This type of attack has been expected for quite some time, but there was no obvious signs of any heightened alert here before the attacks. It has literally come out of the blue. With at least three bombers still on the loose, we're going to be holding our breath for a while .... I must admit, we've subsequently had a bit of a scare at this end; I dropped Mrs. Coops off at the station to catch her train to work. The station had been temporarily closed for approx. 15 minutes for operational reasons (which has never happened before); not wanting to wait for it to reopen, she called me to collect her, and take her to a station a couple of miles away on another line. Had she got on her train as usual (on time), it is quite possible that it was actually the first train to be blown up. To compound the situation, she has since told me that the carriage which was devastated by the device, is the one she normally sits in. I'll be driving her in to work over the weekend, but it's back to using the Underground on Monday - now you know why they say us Brits have a stiff upper lip!! On a professional note, there are literally thousands of CCTV cameras on the Underground (the majority of pictures I've seen have been absolute c**p), and the Police forensic teams are going to have to go through tens of thousands of hours of recordings to try and identify suspects. Whilst our thoughts are with the families and friends of those killed and injured, we can only hope that the authorities have an early breakthrough ...