Red Light Camera & Turning

[andy21]

How do red light cameras work with regards to turning since I have read they take a 2nd picture about a second after the first by which time you would probably be out of sight. The thought ocurred to me as I was travelling along an NSL road to turn left and as I slowed down to turn (after the stop line) I saw the light change to amber. :confused:

[2 Smokin Barrels]

I don't know the answer, but why would a red light camera need to take two pictures?

Surely one of a red light, and you beyond it would do?

[smeggy]

andy21 said:

How do red light cameras work with regards to turning since I have read they take a 2nd picture about a second after the first by which time you would probably be out of sight. The thought ocurred to me as I was travelling along an NSL road to turn left and as I slowed down to turn (after the stop line) I saw the light change to amber.

Once you trip the sensor (there's only one per entrance of crossroads) the camera will take two pics regardless of which direction you turn or how fast you are going.

[smeggy]

2 Smokin Barrels said:

I don't know the answer, but why would a red light camera need to take two pictures? Surely one of a red light, and you beyond it would do?

No it wont as 1 pic alone won’t be able to prove the offender hadn’t been unlucky and was caught at the end of a queue or had simply broken down, prior to the red.

Both pics will be needed to show that the offender carried on through the sensor and wasn't already on the junction (stationary), thereby securing the conviction. So I guess they shouldn't prosecute if a car is in the same position in both pics (I stand to be corrected).


Here's another good reason for 2 pics, speed measurement:

www.pistonheads.com/gassing/topic.asp?h=0&f=10&t=201000

[2 Smokin Barrels]

smeggy said:

2 Smokin Barrels said: I don't know the answer, but why would a red light camera need to take two pictures? Surely one of a red light, and you beyond it would do? No it wont as 1 pic alone won’t be able to prove the offender hadn’t been unlucky and was caught at the end of a queue or had simply broken down, prior to the red. Both pics will be needed to show that the offender carried on through the sensor and wasn't already on the junction (stationary), thereby securing the conviction. So I guess they shouldn't prosecute if a car is in the same position in both pics (I stand to be corrected). Here's another good reason for 2 pics, speed measurement: www.pistonheads.com/gassing/topic.asp?h=0&f=10&t=201000

Okeydokey! 2 pics for speed I was aware of!

['King Deadly]

2 Smokin Barrels said:

I don't know the answer, but why would a red light camera need to take two pictures? Surely one of a red light, and you beyond it would do?

Surely the photo should show you before the red light, otherwise how does it prove it was red as you drove through it?

[2 Smokin Barrels]

'King Deadly said:

2 Smokin Barrels said: I don't know the answer, but why would a red light camera need to take two pictures? Surely one of a red light, and you beyond it would do? Surely the photo should show you before the red light, otherwise how does it prove it was red as you drove through it?

Pic shows the light on red, and you where you shouldn't be!


>> Edited by 2 Smokin Barrels on Friday 19th August 13:29

[smeggy]

'King Deadly said:

Surely the photo should show you before the red light, otherwise how does it prove it was red as you drove through it?

I didn’t quite understand what you meant by ‘before the red light’ (time or distance).

If the sensor was placed before the stop line then all cars legally waiting would trigger it, hence wasting film.
If the photo was to be taken before the light went red, then drivers who (legally?) came to a quick halt just before the red would trigger it, then there is no way of proving if the driver came to a quick halt just before or after the red. Also, there could be contention as it could not be proven when exactly the photo was taken during the amber sequence.

With the current method, an offender has no excuse if caught moving between the two pics showing red lights (unless perhaps giving way to the emergency services).


I’m not an RLC expert, I’m just applying what I hope is some common sense.

['King Deadly]

smeggy said:

'King Deadly said: Surely the photo should show you before the red light, otherwise how does it prove it was red as you drove through it? I didn’t quite understand what you meant by ‘before the red light’ (time or distance).

Yes, I see what you mean. By "before" I meant in front of.

smeggy said:

If the sensor was placed before the stop line then all cars legally waiting would trigger it, hence wasting film. If the photo was to be taken before the light went red, then drivers who (legally?) came to a quick halt just before the red would trigger it, then there is no way of proving if the driver came to a quick halt just before or after the red. Also, there could be contention as it could not be proven when exactly the photo was taken during the amber sequence. With the current method, an offender has no excuse if caught moving between the two pics showing red lights (unless perhaps giving way to the emergency services).

The point is, the photos should prove the light was red as you drove through it.

Look at the top two photos (red Sierra) on this link:-

www.devon-cornwall.police.uk/dcsc/enfotech/redlight.htm

As it happens, because of the white Astra it's obvious the Sierra ran the light. But suppose there were no other cars in shot. In the first photo, the Sierra has already passed over the stop line, so what's to say the light wasn't amber as he drove over it?

Unless of course it's an offence to drive through the red light beyond the junction (i.e. the lights change from amber to red as you're halfway across the junction). But surely this isn't the case?

[Dwight VanDriver]

An American explanation but relevant to UK:

. What are red light cameras?

Red light cameras can help communities enforce traffic laws by automatically photographing vehicles whose drivers run red lights. A red light camera system is connected to the traffic signal and to sensors that monitor traffic flow at the crosswalk or stop line. The system continuously monitors the traffic signal, and the camera itself is triggered by any vehicle entering the intersection above a pre-set minimum speed and a specified time after the signal has turned red. A second photograph typically shows the red light violator in the intersection. In some cases video cameras are used. Cameras record the date, time of day, time elapsed since the beginning of the red signal, and vehicle speed. Tickets typically are sent by mail to owners of violating vehicles, based on review of photographic evidence.

dvd

Tooling down the high street doing 79
I'm a twin pipe papa and I'm feelin fine
Hey man dig that was that a redlight camera sign
(screetch - BANG!!!tinkle)
Transfusioon transfusion
I'm just a solid mess of contusions
Never,never, NEVER gonna speed again
Slip the blood to me Bud.

...if you know where this came from I know where you go...

[bluepolarbear]

smeggy said:

With the current method, an offender has no excuse if caught moving between the two pics showing red lights (unless perhaps giving way to the emergency services).

I wouldn't if I were you they take the 3pts and £60 even if you were moving to make way for an emergency vehicle.

[johnny the prof]

Hey wedgies,
I've been researching gatso's for the past 6 mths,
It actually takes the second pic 1/2 a second later for legal (disputes) and measurement purposes.
ps I am currently working on a device right now, which is built into a car amp case, the device has 4 connections on the rear panel, one power 12V 2 connect to modified number plate lights and the third connection is the trigger, which senses a flash of light, and is located in the car. Once the sensor detects the flash, the main unit sends a 4k pulse to the modified number plate lights, which are charged with 360V subsequently causing a flash of bright light, over illuminating the plate, I've tried to take a picture of my plate, the picture comes out as two bright diamond shapes of light.
There are some bugs which I'm working on, and I'll update soon with some photos.
the prof

[smeggy]

johnny the prof said:

Hey wedgies, I've been researching gatso's for the past 6 mths, It actually takes the second pic 1/2 a second later for legal (disputes) and measurement purposes. ps I am currently working on a device right now, which is built into a car amp case, the device has 4 connections on the rear panel, one power 12V 2 connect to modified number plate lights and the third connection is the trigger, which senses a flash of light, and is located in the car. Once the sensor detects the flash, the main unit sends a 4k pulse to the modified number plate lights, which are charged with 360V subsequently causing a flash of bright light, over illuminating the plate, I've tried to take a picture of my plate, the picture comes out as two bright diamond shapes of light. There are some bugs which I'm working on, and I'll update soon with some photos. the prof

I'm not sure you want to be admitting that in a public forum frequented by police. Still, I'd like to see the results.


It could be easier to buy this:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=7538697161

[johnny the prof]

Yeah that's what I thought, how simple, the cheap flash on ebay, and not the police, phew that was close, as for the law it's for amusing your mates in the pub car park. ere, see if your phone can take a picture of my number plate, go on, bet ya a score, or even preventing the paparazzi from invading ones privacy. so yeah......... the cheap flash solution,
yeah that's what I thought I could get away with.
But sadly I was wrong, It cannot recharge quick enough to counter the second flash, and the auto exposure system on the said camera, compensates.

My system has two independent systems, and the flash duration has been increased and moved slightly, more power, and the whole thing looks just like an ordinary car amp, the number plate lights look the same, totally undetectable,
the prof

[smeggy]

johnny the prof said:

But sadly I was wrong, It cannot recharge quick enough to counter the second flash, and the auto exposure system on the said camera, compensates.

Charge two (large) caps in parallel each via a HV diode, then use a relay to gate the other immediately after the first flash - recharge time won't be an issue

[timtonal]

My dad was an avid photographer and used to have a slave flashgun like the one linked above that triggered when it detected the primary flashgun's flash.

That and a sheet of liquid crystal....

A though experiment of course!

>> Edited by timtonal on Sunday 21st August 07:50