Speed Camera / Slippage Help required
Discussion
Morning all,
Having recieved a 3 pointer (36 in a 30) I am trying to understand slippage, and any other terms that relate to camera's over reading a speed.
Normally I would accept a ticket with grace, and accept i was speeding, but as I know i wasn't (the camera van was outside the house i was in, and i stayed under the 30!) I need to understand this.
I have been kindly sent the photo's from the police, and they show the cross hairs have moved significantly to the left on my number plate. Is this slippage?
Any comments offline to my email are more than welcome, especially from our good friends in Blue. I knwo that most will have an understanding if this, and I'd appreciate the professional opinion.
Simond
Having recieved a 3 pointer (36 in a 30) I am trying to understand slippage, and any other terms that relate to camera's over reading a speed.
Normally I would accept a ticket with grace, and accept i was speeding, but as I know i wasn't (the camera van was outside the house i was in, and i stayed under the 30!) I need to understand this.
I have been kindly sent the photo's from the police, and they show the cross hairs have moved significantly to the left on my number plate. Is this slippage?
Any comments offline to my email are more than welcome, especially from our good friends in Blue. I knwo that most will have an understanding if this, and I'd appreciate the professional opinion.
Simond
Hi,
I have fought unsucessfully a case at the Magistrates Court and Crown court on slippage. If you have a search through some of the threads I have responded to you might get an idea.
I too knew I wasnt going the speed I was stopped at. Considering I was driving a Tuscan which only has curved faces, and that I was targeted at a quarter of a mile away, slippage was a certainty, not a possibility.
Your case is slightly different as you have photographic evidence. You can also ask for the full video recording of the day that they were using the van. They have to let you have this if you ask for it. There yourself or a good solicitor can see that there may be errors in the way the camera was set up or has been giving error readings etc.
Have a look at www.peripoo.com they have loads of information about it and test cases to look at. Let us know how it goes, or if you want some more information about how the court 'sees' slippage let me know, as I believe I have a way forward...
I have fought unsucessfully a case at the Magistrates Court and Crown court on slippage. If you have a search through some of the threads I have responded to you might get an idea.
I too knew I wasnt going the speed I was stopped at. Considering I was driving a Tuscan which only has curved faces, and that I was targeted at a quarter of a mile away, slippage was a certainty, not a possibility.
Your case is slightly different as you have photographic evidence. You can also ask for the full video recording of the day that they were using the van. They have to let you have this if you ask for it. There yourself or a good solicitor can see that there may be errors in the way the camera was set up or has been giving error readings etc.
Have a look at www.peripoo.com they have loads of information about it and test cases to look at. Let us know how it goes, or if you want some more information about how the court 'sees' slippage let me know, as I believe I have a way forward...
www.pepipoo.com in case you have trouble with that link.
The Tuscan presumably has the obvious flat reflective surface, although how you keep a beam on the front plate at 400 yrds is beyond me (and observe it for three seconds before confirming with the instruments).
Good luck to challenging -- if you are sure that you were under the limit then get in there and fight!
The Tuscan presumably has the obvious flat reflective surface, although how you keep a beam on the front plate at 400 yrds is beyond me (and observe it for three seconds before confirming with the instruments).
Good luck to challenging -- if you are sure that you were under the limit then get in there and fight!
Assuming you were caught by a laser/Lidar gun (as opposed to the radar variety):
The gun won’t give a false reading as long as the first flat, vertical surface of your vehicle was targeted throughout. Slippage can only occur if the crosshairs were aimed at the side or top of your vehicle (or other street furniture)
If you really want to fight it, make sure you get the full video sequence including the crosshair location check procedure at the start; it would be useful to know that the laser was aimed properly at your car (you won’t see the location of the actual laser beam in the video).
This should be of use to you:
simond001 said:From my interpretation of your description: No.
I have been kindly sent the photo's from the police, and they show the cross hairs have moved significantly to the left on my number plate. Is this slippage?
The gun won’t give a false reading as long as the first flat, vertical surface of your vehicle was targeted throughout. Slippage can only occur if the crosshairs were aimed at the side or top of your vehicle (or other street furniture)
If you really want to fight it, make sure you get the full video sequence including the crosshair location check procedure at the start; it would be useful to know that the laser was aimed properly at your car (you won’t see the location of the actual laser beam in the video).
simond001 said:The BiB here won’t comment on this issue, probably for fear that their actions will damage their career prospects.
Any comments offline to my email are more than welcome, especially from our good friends in Blue. I knwo that most will have an understanding if this, and I'd appreciate the professional opinion.
This should be of use to you:
catso from another thread said:
The programme can be downloaded at;
Large; www.pepipoo.org/files/inside_out_12-sep-05.rm
Small; http://homepage.ntlworld.com/julie.denton2/insout.wmv
Article here; www.bbc.co.uk/london/content/articles/2005/09/07/insideout_speedgun_feature.shtml
discusses the programme and you can have your say, a certain Steve Callaghan has...
Hi, sorry about the dodgy pepipoo link, I was well corrected, many thanks!
I agree, at 400m it is impossible to hit a number plate, let alone keep it on it for a third of a second.
Now, the LTI20/20 makers have responded to report about slip error that they have error trapping software where if slip error is thought to be in the readings the readout is 'error'. This cannot be the case as on a curved surface there MUST be some slip error, unless we believe that the bean did not move from the number plate, which is quite impossible. In court I showed how if you can hit a car at 400m, you can also hit the 9 or 10 on an Olympic Pistol shooting target, which means you would be in for a medal. To say you could be that accurate on a moving target is rediculous, to say that you didnt just hit the car, it was the 12cm wide numberplate from 400m is just insane.
In these cases, common sense of the impossible situation is thrown out the window as:
1)The PC has been trained to use the equipment, and says he used it properly.
2)The home office have 'Type Approved' the device for use as the manufacturer has designed.
3)The manufacturer says the device works up to 1000m.
4)The ACPO guidelines which are supposed to be mandatory in the use and accuracy of the readings *do not legally have to be followed*.
Without an expert witness, it is impossible to disprove any of the above points. The Magistrates/Judge assume (perhaps rightly so!!) that the device should not be used in the way that it is if it doesnt work, thus it must do...
I agree, at 400m it is impossible to hit a number plate, let alone keep it on it for a third of a second.
Now, the LTI20/20 makers have responded to report about slip error that they have error trapping software where if slip error is thought to be in the readings the readout is 'error'. This cannot be the case as on a curved surface there MUST be some slip error, unless we believe that the bean did not move from the number plate, which is quite impossible. In court I showed how if you can hit a car at 400m, you can also hit the 9 or 10 on an Olympic Pistol shooting target, which means you would be in for a medal. To say you could be that accurate on a moving target is rediculous, to say that you didnt just hit the car, it was the 12cm wide numberplate from 400m is just insane.
In these cases, common sense of the impossible situation is thrown out the window as:
1)The PC has been trained to use the equipment, and says he used it properly.
2)The home office have 'Type Approved' the device for use as the manufacturer has designed.
3)The manufacturer says the device works up to 1000m.
4)The ACPO guidelines which are supposed to be mandatory in the use and accuracy of the readings *do not legally have to be followed*.
Without an expert witness, it is impossible to disprove any of the above points. The Magistrates/Judge assume (perhaps rightly so!!) that the device should not be used in the way that it is if it doesnt work, thus it must do...
Just popped into my local Police Station. Extremely helpful chap rang the photographic unit to get an explanation of the codes on photo's.
He has advised that it would be better to take the 3 points "for all the times I wasn't caught", as he cannot see any way for me to prove I wasn't speeding, and as Northamptonshire Police will not provide any details of camera / calibration or focal point it may prove more costly if I went to court.
He ended by reminding me that a court would percieve the actions of the camera team were fully compliant until I proved otherwise.
(he also mentioned that my number plate was somewhat illegally spaced, must bear that in mind!)
He has advised that it would be better to take the 3 points "for all the times I wasn't caught", as he cannot see any way for me to prove I wasn't speeding, and as Northamptonshire Police will not provide any details of camera / calibration or focal point it may prove more costly if I went to court.
He ended by reminding me that a court would percieve the actions of the camera team were fully compliant until I proved otherwise.
(he also mentioned that my number plate was somewhat illegally spaced, must bear that in mind!)
simond001 said:I would have to agree, but not for the reasons you were given.
He has advised that it would be better to take the 3 points "for all the times I wasn't caught", as he cannot see any way for me to prove I wasn't speeding,
if you were caught by laser/lidar.....
I just realised that the second photo would only be for driver identification, it would have been taken a long time after the speed measurement had completed; hence it won't matter where the crosshairs were placed.
You might aswell contest it, they have to provide all the evidence you ask for seven days before trial, and they usually mess this up somewhere.
You can still plead guilty at this stage, before apearing in court, and will only have to pay an extra £35 in court costs, the bonus is the scameras dont get any of the money then too.
You can still plead guilty at this stage, before apearing in court, and will only have to pay an extra £35 in court costs, the bonus is the scameras dont get any of the money then too.
justinp1 said:
I agree, at 400m it is impossible to hit a number plate, let alone keep it on it for a third of a second.
Is that guess work or from experience.
At 400m the beam will be about 600mm (2 foot in old money) wide so it will be very easy to paint the beam onto the vehicle to get a good reflection.
The bollox mentioned regarding difficult to hit and comparisos with a rifle are nonsense. It would be more accurate to compare it with a shotgun really as the beam aint very thin when it reaches your vehicle at 400m.
I could hold the xhairs on a target 400m away.
The thing is, I'd need a J86x9 lens to do it, with a Vector 700 fluid head. Which looks a bit like this:
Now if any BiB would care to show me their equipment, and the skills needed to hold the frame so accurately, I'd happily take the above back.
Thing is, as not many cameramen can do what's described, I sincerely doubt they will.
The thing is, I'd need a J86x9 lens to do it, with a Vector 700 fluid head. Which looks a bit like this:
Now if any BiB would care to show me their equipment, and the skills needed to hold the frame so accurately, I'd happily take the above back.
Thing is, as not many cameramen can do what's described, I sincerely doubt they will.
This thread in another forum sort of covers some of the issues and contains a few other links. However, every time I read anything related to the site in Israel (which has been around for a while now and is discussing an earlier, larger, LTI unit though the core technology is likely to be little changed) there are subtle differences in the content.
For example, my original understanding of the LTI is that it uses 3 beams and expects to get reasonably consistent results from at least 2 of them else and and error message should be displayed. Whereas the report here suggests that the image representing 3 beams in the LTI is in fact the beams from the 3 different units and purports to show how the target accuracy might be well out of alignment.
Now, if that is the case, a video could well show the simulated cross hairs as pointing at a suitable surface but the actual measuring beam could be anywhere.
www.radardetector.net/LTI2020-Marksman-not-accurate-in-Israel-4370t.php
And then there are these rather sad stories ...
www.radardetector.net/Speed-Trap-Kills-Two-4725t.php
For example, my original understanding of the LTI is that it uses 3 beams and expects to get reasonably consistent results from at least 2 of them else and and error message should be displayed. Whereas the report here suggests that the image representing 3 beams in the LTI is in fact the beams from the 3 different units and purports to show how the target accuracy might be well out of alignment.
Now, if that is the case, a video could well show the simulated cross hairs as pointing at a suitable surface but the actual measuring beam could be anywhere.
www.radardetector.net/LTI2020-Marksman-not-accurate-in-Israel-4370t.php
And then there are these rather sad stories ...
www.radardetector.net/Speed-Trap-Kills-Two-4725t.php
pisstonhead said:
I agree, at 400m it is impossible to hit a number plate, let alone keep it on it for a third of a second.
Is that guess work or from experience.
At 400m the beam will be about 600mm (2 foot in old money) wide so it will be very easy to paint the beam onto the vehicle to get a good reflection.
The bollox mentioned regarding difficult to hit and comparisos with a rifle are nonsense. It would be more accurate to compare it with a shotgun really as the beam aint very thin when it reaches your vehicle at 400m.
Hi,
Just to respond to my 'bollox'...
At 400m the beam will be 1.2m wide.
Even with that, would *you* be able to hit a number plate with a handheld device without a tripod from a quarter of a mile away? And is *that* based on guesswork or experience?
And even if you feel part of the beam has hit the number plate, could you accurately see from that distance which other parts of the car were also hit by the beam. Thus, could you tell which was the point of reference for the device and keep it accurately on that spot following the vehicle for a third of a second?
You can call my analysis 'bollox' if you wish, and I would be glad to see your answer to the above, and even if you would say that a laser beam is more akin to a shotgun, if you can hit a 12cm target from a shotgun a quarter of a mile away, then you are a hell of a shot!!???
At the HQ of a well known GPS camera detector I used a LTI 20-20 to test my GPS device.
At 6ft7" & a reasonably fit 18 stone, I guess I'm at least as strong as your average BIB.
I also did a fair bit of Pistol & smallbore rifle shooting in the past.
I can tell you that I found it almost impossible to keep the laser gun steady for more than a split second at a time. IMO a tripod would be essential to keep it steady.
At 6ft7" & a reasonably fit 18 stone, I guess I'm at least as strong as your average BIB.
I also did a fair bit of Pistol & smallbore rifle shooting in the past.
I can tell you that I found it almost impossible to keep the laser gun steady for more than a split second at a time. IMO a tripod would be essential to keep it steady.
Just for fun..
If you want to keep the shooting analogy then how about lamping?
Shine a torch around a large field at night and you will be surprised how easily you can pick out an animal's eyes at great distances.
The eyes will be the only thing that reflects light right back at you
If you want to keep the shooting analogy then how about lamping?
Shine a torch around a large field at night and you will be surprised how easily you can pick out an animal's eyes at great distances.
The eyes will be the only thing that reflects light right back at you
echo said:
Just for fun..
If you want to keep the shooting analogy then how about lamping?
Shine a torch around a large field at night and you will be surprised how easily you can pick out an animal's eyes at great distances.
The eyes will be the only thing that reflects light right back at you
You probably could! But could you form an opinion of speed before you lamped them?
On a serious note, contrary to popular belief it is not only the reflective number plate which will return the laser beam. The tiny amount of light they need to get a 'reading' means that most objects will, thus the operator has no idea which parts of the car was targeted from that distance, and to a certain extent *which* car! At 400m, 2mm of hand shake will move the beam 2.4m which would be into the other lane of traffic.
justinp1 said:You are right - to an extent.
The tiny amount of light they need to get a 'reading' means that most objects will, thus the operator has no idea which parts of the car was targeted from that distance, and to a certain extent *which* car!
The laser beam will not show up on the video (the IR pulses are far too short). Hence the gun should be checked at the start of each tour of duty to ensure the laser beam is correctly aligned within the crosshairs (in both the vertical and horizontal planes). Always request the full video evidence
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