Safe Speed Forums

Fair enough; they are flash units though.

Here's a law enforcement officer mentioning what they are: http://www.policespecials.com/forum/ind ... pic=80929#

Here's one from another forum: http://forums.pepipoo.com/index.php?sho ... t&p=342130

What about this one from Herts, where the first one's in the UK were installed?
"...Apart from modifications to the housings, the upgrade to digital includes a separate secondary flash pole. The remainder of the sites will be upgraded in the next few years and the obsolete wet film cameras will be phased out..."
Link: http://news.hertsdirect.org/Release.asp ... 03&_cat=16

I don't want to point out the obvious (well I do) but there is a parody..


Okay class, before we discuss speed there’s something you should all know..

Speed leads to accidents, which leads to death, which leads to mass murder and the end of civilisation.

Who is ready to learn about speed?

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The views expressed in this post are personal opinions and do not necessarily represent the views of Safe Speed.
You will be branded a threat to society by going over a speed limit where it is safe to do so, and suffer the consequences of your actions in a way criminals do not, more so than someone who is a real threat to our society.

I'm not going to dispute this, but I don't have the necessary information about these to understand the rationale behind it.
The important bit is the VRM (well the camera obviously isn't not for driver ID). UK VRMs are retro-reflective, hence the flash bouncing from the VRM will return back to the source (the main camera). A slave flash won't aid illumination of that type of plate as it will be offset away from line of sight of the main camera (otherwise it will block the view of the camera).

Can you explain why this is slave is required?
- Is it to aid illumination of non-retro-reflective plates?
- Is it to aid illumination of the more distance graduation marks? (which I thought are semi-retro-reflective anyway)
- Is it to aid illumination of other parts of the vehicle - to help determine the position of the vehicle relative to those graduation marks?




Oh look, there RTTM again. Looks like RTTM still hasn't been addressed, huh greenshed

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

As I've sqaid before the answersto queations about these devices don't all seem to come from the same hymn sheet ( so to speak) .Locally I know of four cameras with this mod and one without .That and the aerials ( and one answer from my local lot -to pass info to local police ) -could there be another usefor these units which accounts for the smokescreen when asked .Again ,perhaps it's just coincidence ,but locally three out of the four with the addition form a triangle on roads into town from one estate .The more answers I hear ,the more I think I'm listening to a camera version of "call my bluff" -which makes me wonder just what are they trying to cover up .

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lets bring sanity back to speed limits.
Drivers are like donkeys -they respond best to a carrot, not a stick .Road safety experts are like Asses - best kept covered up ,or sat on

I have been notified that these are ANPR only and it is the electrical link from gatso's nearby that set their location. I will try to verify this more seriously soon.

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Safe Speed for Intelligent Road Safety through proper research, experience & guidance.

The VRM only needs to be photographed once; this is done with the aid of the main flash; the secondary flash doesn't need to be used for this in the secondary check images although they do help.

1. No although it does help
2. Yes
3. Yes
4. Digital cameras need a lot of light at night to maintain clarity in a colour image; the secondary flash helps this and prevents the need to revert to monochrome.

Good luck but you should inform your informant that they are wrong.

Thank you for your clear answers greenshed.


I'm surprised by this. I would have thought the manufacturers of these pricey speed cameras would have sprung for a decent sized imager (light gathering power and all that) instead of relying on another separate module. It is currently accepted by photo enthusiasts that equivalent sized (35mm) digital imagers , with the same resolution, beats film in terms of noise and MTF (contrast between pixels) – by quite a margin.

edited to add: Now I think about it, flash power can’t be much of an issue here.

I know of other gatso installations which must over 3 lanes, the 20 deg angle means that flash must be quite powerful to work over the distance required for the third lane. This should not be an issue for the single lane set-up within the presented scenario (the photos earlier in this thread) because this one only has to work over 1 lane (much closer).
Given this, can you explain how the availability of light is an issue?


This also doesn't explain the presence of the aerial. The obvious answer is it could be an RF link to the gatso (for triggering the slave flash), but there hasn't been mention of one on the gatso.
This begs the question: what does this slave communicate with?

There is another set of questions here that could also do with clear answers, thanks.

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

Most puzzling, if an official response has been that it is a flash, but that the aerial is for communicating with someone, then what is it communicating? "I just flashed"?

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Regulation without education merely creates more criminals.

Is it there too to enable further convictions because of a prior failing which then may bring into question all prior convictions ?

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Safe Speed for Intelligent Road Safety through proper research, experience & guidance.

You are always at liberty to develop a camera system yourself and propose it to Gatso to replace theirs. If the problem of digital photography of vehicles between 20 - 150+ mph was a simple task then there would be a lot of cheap cameras on the market perhaps.
The aerial isn't fitted on all units and is not connected to the operation of the flash unit; it just gets mounted on there when it is required to be fitted at some locations.

Perhaps it's there to illuminate the darkness that appears to be where your knowledge is on this matter.

The camera works without the flash but not as well as it does with it.

The answer to your question is....No.

This from the man who won't answer a simple simple question from Robin.

Emperor Greenshed has no clothes methinks. Or maybe just a fig leaf; a very small fig leaf

_________________
The views expressed in this post are personal opinions and do not necessarily represent the views of Safe Speed.
You will be branded a threat to society by going over a speed limit where it is safe to do so, and suffer the consequences of your actions in a way criminals do not, more so than someone who is a real threat to our society.

To summarise: your first answer was about lighting, I explained why lighting can't be an issue in the scenario described earlier in the thread, and you reply with the standard disingenuous answer of "so you think you can do better" without addressing my concern in any way

I don’t know if you’ve noticed, but there are already a lot of cheap cameras on the market, not that it matters - at ~£30k (for a wet film version), gatsos aren’t exactly cheap are they!

I won't let your diversionary tactic hide the fact you didn't actually address the reasonable technical concerns given. Is this the standard level of answer given by an expert witness in court?
I now strongly suspect your original answer isn’t complete and possibly inaccurate; the darkness of knowledge in this matter appears to be coming from the blackest/darkest pot


When exactly would it be required?
Again: what does this slave communicate with "when it is required"? In this case it was clearly fitted, but there doesn't seem to be one on the gatso, so implying the RF link is not with the gatso.


Will you continue to evade these too?

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

There is a flash put in that is additional to the primary flash; light therefore would seem to be at issue; it is at issue.

My earlier answer should indicate a challenge to you; I am glad it did; it isn't supposed to be sarcastic as it is a genuine challenge for you to show how, with your technical knowledge, you can come up with a better system that has been used in this particular solution. There may be better solutions, granted but have they been developed for and been tested to Type Approval standards? The solution at issue has been as the approval is available to the public.

I won't answer all of your questions for obvious reasons; what would you have me do? Place the design drawing on the web?

The answer to the OP's question is that the objects are a secondary fill-in flash unit; you can use your mastery of the electronic and telecommunications world to work out what the rest of the system is but the object is not an ANPR system nor is it a CCTV. There are very few police officers who have dealings with this sort of camera system so Claire's sources will not necessarily know what the system configuration is or, more to the point is not.

Good luck with your imagineering.

What is it? A Flash Unit.

Lol, try reading that second paragraph again without your obnoxious conceited head on Greenshed, you want Steve to propose a better system, and then you want to say that it's not type approved? What planet are you from!? You want someone on an internet forum, who is against camera enforcement, to not only propose a technically superior system to the dross we see on our streets, but have it put through Home Office Type Approval, before you will admit shortcomings in the current incarnations!?

Boggle!!!

So what is this aerial that is sometimes required, and why is it only sometimes required, and why is it required to be within the GATSO radar's beaten arc? Enough charlatanry!

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Regulation without education merely creates more criminals.

You completely misunderstood my response - I don’t see what the problem is; I don't see a challenge that should need solving.
I repeat myself: If a gatso can work over 3 lanes (and hence much longer distances), and digital is generally better than film, why would a digital system need such a lighting aid for comparatively close range operation? This is one of the reasons why your answer doesn’t make sense.


What’s that? Are these answers classified Isn’t that the typical response from a expert witness in court
Alternatively: you do not know the answer?


Reconcile your answer (of lighting) with the close range of the described scenario and that digital is better than (or at least as good as) film (all else being equal); or acknowledge your explanation doesn’t make sense.

That’s your challenge. "It isn't supposed to be sarcastic as it is a genuine challenge for you to show how, with your technical knowledge, you can come up with those" answers.

And again:
- When exactly would this aerial be required?
- what does this slave communicate with "when it is required"? In this case it was clearly fitted, but there doesn't seem to be one on the gatso, so implying the RF link is not with the gatso.

I would also ask that you answer the other posts in other threads, but I suspect your answer will be continued diversions.


I have no doubt it flashes, but is that really all it does?


Good luck with demonstrating your reasoning to your answers!

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

Do you really believe that digital cameras are better than the film? Detail and dynamic range of the photo response is poorer with digital cameras than the film as I understand it. A filler flash is used with the digital camera to make up for the poorer response of digital systems as almost all digital spot speed enforcement systems employ.

There is no RF communication between the flash and the camera unit.

Because you can't, primarily because you have no affiliation with with any law enforcement agency, or indeed manufacturer of enforcement devices, please stop the charade, it is exceedingly tiresome.

Your understanding is wrong.
For the same size imager, digital is superior to film in terms of noise and contrast.
A short summary of history: many folks used to judge digital against film simply by the resolution. Once digital caught up with film (resolving to 5 micron square on a full frame imager), folks started comparing the two techs. It was found that digital photos were so much better in general (with 35mm imagers), even though the resolution was the same - because of noise and MTF (contrast to adjacent pixels). Digital photography has opened a new world of "Über Clarity" not seen during the film era; lens design (and marketing) has become much more technically aggressive – because it can now be measured.

The dynamic range of digital imagers are almost always greatly increased by use of non-linear ADCs (I've never seen a linear digital imager, not even on top-end still cameras). Use of filler flash also applies to film (dark is dark regardless of what captures it). RAW capture and processing will bring out those shadows anyway (why assume linear and 8-bit?).
Granted larger digital imagers are more expensive, but that still pales in comparison to the cost of a speed camera (and the maintenance of the films).
If those tiny little video digital imagers are good enough for SPECS and their comparatively feeble illumination...

I ask again: why use a slave when enforcing 1 lane, when 3 lanes (inverse square law) didn’t need one?
Unless you can demonstrate that film is more than 9 times better than digital....


Very interesting!

And again - again:
- When exactly would this aerial be required?
- what does this slave communicate with "when it is required"?

In short, this unit is clearly somewhat more than a simple slave flash if it has an RF comms link which does not form part of the slave trigger circuit – yes or no?
<slowly, slowly, catchy monkey>

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign