Why and in what circumstances would you want to do this? Are going to construct your cardboard and foil thingy and walk down to your nearest camera and wave it about a bit? Are you going to keep this stuff in the back of your car and, if you think you have zapped, park up, walk back and wave it about? It won't work anyway and I can't envisage any circumstances when you would use it it anyway. If WE are the ones who are stupid (we aren't BTW) please enlighten us Oh Wise One!
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Yes, I have searched the Internet and I couldn't find anything other than a Mythbusters episode where they proved that speeding birds (of the winged type) can set cameras off. The interesting point was that the camera made some dodgy speed recordings.
If the answers are on the Internet then maybe someone could post a link?
AS - I'm not calling anyone on this board stupid, not even willdebeest - the comment is aimed at that one post, not the poster and not anyone else. I've read many of willdebeests posts and they are generally very good. If you think my post was dumb then why reply with an equally dumb post?
The question is completely hypothectial (not sure how you spell that), I'm not going to try it out, I'm just curious. I've never been zapped by a speed camera and don't itend to. So it's not something I would ever consider. Doing this for real would be stupid. :)
I've been reading this board for a few years now and have never seen this topic discussed, maybe it has, but I've not seen it.
I don't really know how the cameras work but my understanding was that they use radar. I also understand that aluminium will reflect radar. Therefore being able to set off the camera, I assume the foil would need to be moving or possibly vibrating for the doppler effect to work. Maybe someone smart could elaborate?
I'm not saying that this would work, I'm asking 'would it work?' If not, then why not?
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Chaff (strips of tinfoil released by aircraft) is used for two reasons - one to confuse a radar guided missile for a few seconds, by giving it multiple targets, in the hope that it will lock onto a slower moving, closer piece of chaff, and in WW2, chaff was dropped, notably on D-Day, to give the German radars the impression of a convoy moving towards France where there was no convoy on the surface.
Chaff has no application in the case the OP describes.
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Chaff (as its called now) or Window (as its WW2 code name was known) was a well know flaw with radar systems - bundles and bundles (tons and tons in fact) of aluminium foil strips cut to half radar wavelengths. Both the Germans and the Allies knew of its properties but neither side wanted to introduce it in case the other had not thought of it. It was in fact feared to be a Radar doomsday weapon. All it did was blind the radar.
Radar of the day did not measure speed, but height and bearing. Speed was measured by plotting, time and trigonometery, and that was windows/chaff main failing. It had very little forward motion, and hence a short period of plotting would reveal it for exactly what it was. Your radar was still blind but you knew chaff was being deployed.
The cure was to switch radar frequencies frequently and use a frequency outside the half wavelength of the chaff strips.
To get to the orginal posters question, if someone had deployed chaff into trees around the camera site, it would not affect the speed readings as the chaff is not actually traveling. Its presence however might be enough to cloud the case beyond reasonable doubt in court.
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TourVanMan TM < Ex RF >
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They use laser technology not LF radar they only real way to fool them is to either chop them down,set them on fire,or better still drive at the correct speed limit and then the question is not required.
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You could borrow a large metal refuse bin, paint an imaginary number plate on it, and then push it along the road as fast as you can towards the speed camera. Try this a number of times, at a range of different speeds, and see if you can make the camera flash. If the camera does not respond, it may be because it has failed to recognise the device as a car. In that case you need to add the words Kevin and Shaz at about upper windscreen height. There is no point in adding a Baby on Board sticker at the rear, because the camera, like everyone else, will just find it irritating and pointless.
Good luck with your research. Do write and tell us about it.
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....You could borrow a large metal refuse bin.....
But wouldn't it be better to take the large metal bin and just lower it over the camera?
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pmh (was peter)
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This is getting silly!
I thought everyone knew how to handle a camera that's had the temerity to flash at you.
You just go back there later with your heavy breakdown crane; hook the winch cable round the pole, drive off and then throw the pesky thing into the river - sorted!
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I seem to recall some time back hearing about some kids who threaded a bit of string down through a tin can and then stood next to the camera whirling it. I've no more details, but I recall it was reported that this set the camera off ! Presumably then if it had old-fashioned film in it you could soon run it dry. And then I suppose, climb back into your car and re-trace your travel. Oh dear, what a bore..........
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So if they use lasers, then surely the same principle of reflecting the laser light back would also trigger the camera?
The kids with the tin can is the effect I was thinking of. I.e. a reflective surface briefly moving fast enough for the camera to be set off.
Nice ideas with the metal dustbins, although the accepted practice round here is to go back late at night with an old car tyre and a can of petrol.
While the sillyness of this thread is fun, I'm really interested in the science of it more than anything. Having never been caught by a speed camera I don't actually have any need to foil the cameras, just curiousity needing to be satisfied.
I know for a fact that there are some very smart people on this forum, hopefully one of them will be along soon with the answer!
:) :) :) :0)
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You want a smart answer - then drop this topic.
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All static Gatso cameras are presently RF doppler not Laser as they specifically have to be aimed using sights/cross hairs to idenify the vehicle in the main beam. Laser technology is not type approved for unmanned static use. An RF refective object of about 0.3 of a square metre traveling at constant 53ft a second i.e. 36/37 would trigger the detector and flash. However a rotating reflective panel is only travelling at the require steed for a split second when 90 degrees to the camera, the rest of the time it is either accelerating or deaccelerting towards or away from the camera. To reduce false triggers, the detection circuitry requires the dobbler to be relatively stable for a period of time before it triggers the two flashes at 0.5 of a second apart. There are other camera that use embedded road sensors and do not transmit any RF thus not detectable with speed trap detectors. If I were you I would stay off the 'moonshine' and get a life. Regards Peter
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i dont really see what the problem is..
a question or two was asked and if people know the answer then answer it.. if they dont... well fluffy dice away....
moonshine,, interesting questions.. dont know any of the answers, but i had another question..especially for the people hear who never answer something correctly unless they like it..
my question to this topic is...
quite often cars/van/bikes etc have flappy flying things around thier cars.. flags banners st georges flags etc etc
so on the same topic as moonshine...what if they add ons were reflective..would they interfere with the readings??
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Good luck with your research. Do write and tell us about it.
Is that not a typo? Didn't you mean 'Don't write and tell us about it'?
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