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Old 29th August 2016, 08:46   #46
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

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Originally Posted by amitk26 View Post
I use the stalk to flash and probe the distance ahead occasionaly on disolute roads
Absolutely..! That is how I use my high beams. When on a new road and am not sure about the fatalities ahead, I probe and ping with the high beam for 1-2 seconds. Gives a great sense. No point driving HB. But most people use HB here. If I can manage, I slow down, pull in left, and let such cars pass. It is annoying.
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Old 29th August 2016, 22:47   #47
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

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Absolutely..! That is how I use my high beams. When on a new road and am not sure about the fatalities ahead, I probe and ping with the high beam for 1-2 seconds. Gives a great sense. No point driving HB. .
So you're driving into the dark when you needn't be. I hope your speed is such that you can stop within that low-beam distance.
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But most people use HB here. If I can manage, I slow down, pull in left, and let such cars pass. It is annoying
It is just as vital to dip when there is a car in front as it is for an approaching vehicle.
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Old 30th August 2016, 01:26   #48
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

Yes colour temperature of the light can make a difference as human eyes have varying levels of sensitivity to different coloured lights. Our eyes have greatest sensitivity to green light and least to red light. So lights of equal intensity/lumens in the two colours will be perceived as brighter and dimmer. Red light also has a lesser effect on our night vision.
3000k lights have more red in their spectrum and 6500k has more green/blue which is why they might have a more dazzling effect
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Old 30th August 2016, 03:15   #49
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

I seem to remember that the red-light/night-vision thing turned out to be a myth. But I haven't googled it yet.

I know that the red/green/white lights of lighthouses etc have different visibility distances, so yes, there must be something in this temperature/brightness thing. I just find it hard to believe that a cold white is noticeably more dazzling than a warm white.

I guess I'd better go google
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Old 30th August 2016, 08:07   #50
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

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Originally Posted by Thad E Ginathom View Post
So you're driving into the dark when you needn't be. I hope your speed is such that you can stop within that low-beam distance.
It is just as vital to dip when there is a car in front as it is for an approaching vehicle.
If your beam is adjusted as per spec that is 75cm height at 25m distance low beam gives viability till 500 to 750 meters atleast depending on how good the reflectors are. If you turn on high beam the immediate vicinity and curbs become dark. So
I don't see why one should use high beam.

The only reason people are blinding others is that they dont know how to use a phillips screwdriver to adjust beams most A.S.S people also have zero idea about beam adjustments over here.
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Old 30th August 2016, 08:11   #51
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

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Originally Posted by amitk26 View Post
If your beam is adjusted as per spec that is 75cm height at 25m distance low beam gives viability till 500 to 750 meters atleast depending on how good the reflectors are. If you turn on high beam the immediate vicinity and curbs become dark. So
I don't see why one should use high beam.
This is interesting. can you share the exact spec so I can take it up with my FNG/ASS accordingly?

Your point on high beam is spot on. It is also the reason why I felt extremely unsafe with XTreme Vision during night driving amid heavy rain. Thx!
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Old 30th August 2016, 09:09   #52
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

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If your beam is adjusted as per spec that is 75cm height at 25m distance low beam gives viability till 500 to 750 meters atleast depending on how good the reflectors are.
Did you mean 50 to 75 metres?
I dont see how conventional single reflector or dual beam headlight's Low Beam can be adjusted to illuminate 0.5KM to almost 1KM ahead. Active headlights probably can.

Last edited by Sankar : 30th August 2016 at 09:10.
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Old 30th August 2016, 10:35   #53
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

I don't if this has been posted before, the first test on headlamp effectiveness, its a US test, so most of the models mentioned aren't as popular here, if they are sold at all.
http://www.iihs.org/iihs/news/deskto...ed-improvement
An interesting take on cutting edge tech
Curve-adaptive systems don't always lead to better ratings. The Cadillac ATS, Kia Optima and Mercedes-Benz C-Class all earn poor ratings even when equipped with adaptive low and high beams.
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Old 30th August 2016, 14:08   #54
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

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Originally Posted by amitk26 View Post
If your beam is adjusted as per spec that is 75cm height at 25m distance low beam gives viability till 500 to 750 meters atleas ...


I think you have metres mixed up with feet?

Anyway, you are not using your high/low beams according to what I understand as international good practice. Used properly, your high beams will never dazzle anyone, because you won't be using them when there is anyone to dazzle.
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Old 30th August 2016, 22:39   #55
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

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Originally Posted by Thad E Ginathom View Post
I seem to remember that the red-light/night-vision thing turned out to be a myth. But I haven't googled it yet.

I know that the red/green/white lights of lighthouses etc have different visibility distances, so yes, there must be something in this temperature/brightness thing. I just find it hard to believe that a cold white is noticeably more dazzling than a warm white.

I guess I'd better go google

Thad I guess the 'myth' part is about SAS commandos shining red light in their eyes to improve night vision before going on a dark mission. That part is false but the fact that red light doesnt affect night vision as much as other colour lights is true
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Old 31st August 2016, 18:40   #56
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

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Thad I guess the 'myth' part is about SAS commandos shining red light in their eyes to improve night vision before going on a dark mission.
Good grief, that sounds crazy! No... never heard it.

My experience comes from sailing. We had a red light over the navigation table, and the reasoning was that it was supposed to affect night vision less... you need to get back on deck and see in the dark (actually, nearly-dark: no-one can see in total darkness).

It was accepted "fact," and standard equipment on boats. Just like yellow fog lamps was accepted "fact" back in 1950s: how many do you see now?

So I never questioned it, but one day, I heard it turned out not to be true. I didn't take a lot of notice, because I stopped sailing during a period of ill health and didn't get back into it.
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That part is false but the fact that red light doesnt affect night vision as much as other colour lights is true
OK, so I did google it. Take a look at this Retaining Night Vision And for a more technical approach, this Stackexchange page.

it doesn't seem completely dogmatic either way, but as I read it, it suggests that intensity is the key, not colour.

(More reading to do, but UPS about to shut down PC....)

Edit... Power back, so I can relax a bit. If you find any good sources to suggest otherwise, please do post them. Will read with interest.

Last edited by Thad E Ginathom : 31st August 2016 at 18:45.
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Old 31st August 2016, 18:54   #57
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

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Originally Posted by amitk26 View Post
If your beam is adjusted as per spec that is 75cm height at 25m distance low beam gives viability till 500 to 750 meters atleast depending on how good the reflectors are.
Using little bit of math here
Visibility considered at 600 meters (avg)
Speed at 100 kmph

At 100 kmph, with 600 meters of visibility, one has a reaction time of exactly 1 second, unless I did the math completely wrong here.

EDIT: I did get it completely wrong. It will be quite a lot of reaction time. Would be around 45 seconds. That's a lot. I doubt one can see 40 seconds ahead at low beams. 2-5 seconds would probably be the maximum visibility in terms of time
Hence the visibility of 500-750 meters is completely incorrect.

Last edited by vinit.merchant : 31st August 2016 at 18:57.
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Old 31st August 2016, 21:03   #58
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

Is it really suggested that low beam gives 600m of illumination? That's over half a km. I doubt high beam gives that much. Have I got these numbers confused?
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Old 31st August 2016, 21:32   #59
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

There have been too many headlight modifications on cars. Now that there are umpteen varieties of cheap chinese products available in the market, these kits are seen even on motorbikes and autos

The law is for good. But I wonder if our cops would steer the law in a way it is supposed to be done which I highly doubt...
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Old 1st September 2016, 10:15   #60
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Default Re: Cops pull the blinds on dazzling headlights in Chennai

Let me add my tuppence worth. Modern headlamps are so well computed that 'stray' light outside the main beam is almost non-existent. So people have issues with objects outside the main beam. Such obstacles abound in Mera Bharat Mahaan. As a result both driving on Full Beam and with fogs has increased.
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