Idea

[thehollowmen]

Erm - so light directed at your bike, at the speed of light, is detected, then another light, travelling at the speed of light, is flashed back? Hmmm - I can't see it working. Even taking into account any latency in the electromatronic circustree. Love to be proven wrong though.

They hold the shutter open for about 1/60 of a second or slower with a flash. This is to time the camera with the flash, otherwise the shutter will open and close before the flash fires. I don't really know why this delay is there...

This allows plenty of time for your (charged) flash to recognise their flash and bat one back. I have played with this a lot with standard cameras. Those slave flashes fire back and will show up in that 1/60 of a second with no problems.

[thehollowmen]

So - photon particles travelling at 186,000 miles per second (Kmps) leave the camera, they then hit the detector circuit on the bike, the detector circuit then does it's stuff, recognising the particles, processes the information (depending on the design) then sends an instruction to a light source of some description on the bike, activating it, which is then fired back at the camera at 186Kmps.

In this time the initial light source from the camera would have hit the bike and have been relected back to the camera. Would it not? I can't see the detector circuit detecting the light particles, switching on a light source (not a filament bulb - they take far too long to switch on) and then for that light radiating from the bike reaching the camera, in effect temporarily blinding it, before the camera has recorded the initial reflection. And if the bike is moving you also have to consider doppler shift.

What you've got to remember is the camera shutter is held open for 1/60 of a second. Pleeeenty of time at those speeds.

[thehollowmen]

I think the limiting factor for this device is going to be making sure the transisor / relay is faster than half the police shutter speed.

[Biff]

What you've got to remember is the camera shutter is held open for 1/60 of a second. Pleeeenty of time at those speeds.

I must be missing something - How? A serious question, as light would have travelled around 3 thousand miles in that time, without considering the effect of doppler shift.

[Ixion]

Eh ? You mean how is the shutter held open ? With springs and cogs and little motors and stuff. Remember, the film is chemical, not electronic.

[Biff]

Eh ? You mean how is the shutter held open ? With springs and cogs and little motors and stuff. Remember, the film is chemical, not electronic.

Erm - no. What I meant was how does it help that a shutter is held open for 1/60th of a second. Because in this time the detector on the bike is expected to detect, processes and activate a pre-charged light to fire a light back at the camera before the light originating from the camera bounces off the bike and returns to the camera lens.

The originating light wouldn't be detected before it hit the bike, it would be detected just after it due to latency within the detectors circuitry. So the light source would have to leave the bike before the camera's reflected light in order to work. Or at least get to it off within a couple of mS in order to over expose the chemical paper before the lens closed. If indeed they still use chemical paper here (they use digital cameras in the UK).

I'm not saying it's not possible. I'm just not convinced at this stage.

[heavenly.talker]

Here's an idea...

Don't go more than 9 kms over the speed limit where there is likely to be a camera! lol

[Ixion]

..Or at least get to it off within a couple of mS in order to over expose the chemical paper before the lens closed. If indeed they still use chemical paper here (they use digital cameras in the UK).

I'm not saying it's not possible. I'm just not convinced at this stage.

Yes, the "flood" light would get to the emulsion after the reflected light from the camera flash. But that's OK it will still overexpose the film.The original light from the camera flash will imprint , turning the silver halide black here and there as appropriate. Then the flood light comes in through the still open shutter and turns everything black. Or blackish. The original image is lost in the overexposure. 1/60 second is lots of milliseconds. All this assumes classical emulsion film technology. If it's digitidolly, that's a different ball game, which I know nuffin about .

[R6_kid:Me]

hmm, i was just thinking, those 'black' lights do a pretty good job of screwing things up... what if you just had ur plate coated in a paint with the same properties as 'black' lights... and a few high powered LED's shining on it. You wouldnt see it during the day, would stand out at night, and when the light flashes combined with the LED's im pretty sure it would just look like one blurry mess.

[Biff]

Yes, the "flood" light would get to the emulsion after the reflected light from the camera flash. But that's OK it will still overexpose the film.The original light from the camera flash will imprint , turning the silver halide black here and there as appropriate. Then the flood light comes in through the still open shutter and turns everything black. Or blackish. The original image is lost in the overexposure. 1/60 second is lots of milliseconds. All this assumes classical emulsion film technology. If it's digitidolly, that's a different ball game, which I know nuffin about .

Ahhhhhhh.

[justsomeguy]

A mate assures me that at 200kmh+ the cameras wont get you. Recons it is to do with the timing and the exposure etc. But I have not been game to verify this though.
Knowing the guy, I am sure he has.

You are growing more and more naughty everyday........

TopGear conducted an experiment to test how fast you need to go to get out of the camera's range.

The resulting speed was around 170mph or 272kmph they did it in a TVR Tuscan on a closed runway.