MtB Posted January 25, 2017 Report Share Posted January 25, 2017 Does anyone know the brightness (in lumens) of a car headlight on main beam? Link to comment Share on other sites More sharing options...
Wanderer Vagabond Posted January 25, 2017 Report Share Posted January 25, 2017 The trouble is, it turns into an arms race doesn't it. When you go out with your 400 Lumen head torch you can only see the dog shit until someone comes the other way with a light the same as yours shining it at you, because yours is dazzling them. Then you'll need a far brighter light! I dunno, with two floodlights illuminating the towpath you should be able to see every last bit of dog sh*t, shouldn't you? who mentioned tunnels? 'Twas an example of when you can have too much light Does anyone know the brightness (in lumens) of a car headlight on main beam? about 1200 lumens I think Link to comment Share on other sites More sharing options...
Richard10002 Posted January 26, 2017 Report Share Posted January 26, 2017 (edited) a quick google suggests dipped about 700 lumens and main beam about 1200 lumens https://www.bikeshophub.com/accessories/bike-lights-e-415.html "Light is measured in lumens (a.k.a. candelas). It takes an alert person about 1.5 seconds to react to something they see ahead of them -- although this varies greatly depending on the person and the situation. A single car or motorcycle low-beam headlight is about 700 lumens. Motor vehicles need bright lights because of their speed. A motorist traveling at 60 mph sees a dog in the road 200 feet ahead, he/she has about two-and-a-quarter seconds to react. A cyclist traveling a 15 mph has nine seconds to react to the same dog. (It could even be a different dog.) So for a typical bike commuter or casual cyclist a 740-lumen bike headlight, such as the Cygolite Turbo 740, is more than bright enough to help illuminate potential problems in the road, and to give the cyclist time to react -- and that's assuming the cyclist is otherwise in absolute darkness. However a mountain biker speeding down a trail at night needs much more light to have the same level of situational awareness. A commuter could probably spend a little less money and have all of the reaction time he/she will need. " Thus, in terms of reaction time, a walker like us ambling along the towpath, or wherever, needs many fewer lumens than the cyclist. Edited January 26, 2017 by Richard10002 Link to comment Share on other sites More sharing options...
hounddog Posted January 26, 2017 Report Share Posted January 26, 2017 a quick google suggests dipped about 700 lumens and main beam about 1200 lumens https://www.bikeshophub.com/accessories/bike-lights-e-415.html "Light is measured in lumens (a.k.a. candelas). It takes an alert person about 1.5 seconds to react to something they see ahead of them -- although this varies greatly depending on the person and the situation. A single car or motorcycle low-beam headlight is about 700 lumens. Motor vehicles need bright lights because of their speed. A motorist traveling at 60 mph sees a dog in the road 200 feet ahead, he/she has about two-and-a-quarter seconds to react. A cyclist traveling a 15 mph has nine seconds to react to the same dog. (It could even be a different dog.) So for a typical bike commuter or casual cyclist a 740-lumen bike headlight, such as the Cygolite Turbo 740, is more than bright enough to help illuminate potential problems in the road, and to give the cyclist time to react -- and that's assuming the cyclist is otherwise in absolute darkness. However a mountain biker speeding down a trail at night needs much more light to have the same level of situational awareness. A commuter could probably spend a little less money and have all of the reaction time he/she will need. " Thus, in terms of reaction time, a walker like us ambling along the towpath, or wherever, needs many fewer lumens than the cyclist. Unless, of course, they are totally pissed off with being blinded by aggressive commuters and want to point out that their choice of lighting is seriously anti-social. Link to comment Share on other sites More sharing options...
Guest Posted January 26, 2017 Report Share Posted January 26, 2017 (edited) The trouble is, it turns into an arms race doesn't it. When you go out with your 400 Lumen head torch you can only see the dog shit until someone comes the other way with a light the same as yours shining it at you, because yours is dazzling them. Then you'll need a far brighter light! This has happened with cars/road vehicles over the years. People used to drive around towns at night on their "sidelights" when I was a sprog. Some people decided (rightly or wrongly) it was better to drive on dipped headlights. This meant that those on sidelights became "invisible" in front of those on headlights and had to do similar. Then came halogen headlights and so it goes. Some headlights now can burn the retinas out of our eyes. We wouldn't cope very will if we had to cope with a little slit of light as in WW2. Edited January 26, 2017 by Guest Link to comment Share on other sites More sharing options...
Jess-- Posted January 26, 2017 Report Share Posted January 26, 2017 This has happened with cars/road vehicles over the years. People used to drive around towns at night on their "sidelights" when I was a sprog. Some people decided (rightly or wrongly) it was better to drive on dipped headlights. This meant that those on sidelights became "invisible" in front of those on headlights and had to do similar. Then came halogen headlights and so it goes. Some headlights now can burn the retinas out of our eyes. We wouldn't cope very will if we had to cope with a little slit of light as in WW2. and now we have the LED Daylight Running Lights fitted to most (if not all) new cars Link to comment Share on other sites More sharing options...
Richard10002 Posted January 26, 2017 Report Share Posted January 26, 2017 and now we have the LED Daylight Running Lights fitted to most (if not all) new cars Good idea IMHO Link to comment Share on other sites More sharing options...
Guest Posted January 26, 2017 Report Share Posted January 26, 2017 and now we have the LED Daylight Running Lights fitted to most (if not all) new cars True. My car is too old to have these, but it seems no vehicle is complete now without these LED lights that do all kind of weird things when the indicators light up etc. I can understand lights that illuminate automatically at certain light levels, but don't see the need to have them on constantly on cars etc. I think they are a good idea on motorcycles which can be difficult to see sometimes. I always wore a dayglo jacket too when I was into bikes. Link to comment Share on other sites More sharing options...
WotEver Posted January 26, 2017 Report Share Posted January 26, 2017 I always wore a dayglo jacket too when I was into bikes. I always rode with dipped beam headlights - so did the cops on their Nortons and later BMWs. The old-school DRLs Link to comment Share on other sites More sharing options...
Jess-- Posted January 26, 2017 Report Share Posted January 26, 2017 I can see pros and cons for the daylight running lights. they were originally intended only for electric vehicles since they could move with no audible warning (engine noise) but now seem to be fitted on everything, I wonder how long before somebody gets hit by an older car after they assumed that it can't be moving because it hasn't got lights on, In no way do I make light of being hit by a car.... been there done that (turns out I bounced quite well at 11 years old and suffered nothing more than a grazed hip). I find it interesting what is happening with led lights now is in a lot of cases what was illegal a few years ago, things like the indicators that light up in sequence or the brake lights that switch from a solid light to a strobe effect when a certain amount of braking force is used. Link to comment Share on other sites More sharing options...
Guest Posted January 26, 2017 Report Share Posted January 26, 2017 I think rather than sticking lights all over cars so that they resemble a Christmas tree, it would be better for drivers to put their pi55ing phones away whilst at the wheel, and look where they are fcuking going. Link to comment Share on other sites More sharing options...
Richard10002 Posted January 26, 2017 Report Share Posted January 26, 2017 (edited) I think rather than sticking lights all over cars so that they resemble a Christmas tree, it would be better for drivers to put their pi55ing phones away whilst at the wheel, and look where they are fcuking going. I think it would be good if they did that in addition. Edited January 26, 2017 by Richard10002 Link to comment Share on other sites More sharing options...
Guest Posted January 26, 2017 Report Share Posted January 26, 2017 I think it would be good if they did that in addition. Maybe. It is a difficult thing to measure as to how effective such devices as daytime lights are. Also there is a theory that we get used to such things making them ineffective. I can see this being true, thinking back to when hazard warning lights first hit the car market (VW?) When driving you would notice immediately a car with its hazard lights on, whereas now everybody has them, use them for the wrong reasons, and we don't tend to notice them as much. Link to comment Share on other sites More sharing options...
cereal tiller Posted January 26, 2017 Report Share Posted January 26, 2017 I always rode with dipped beam headlights - so did the cops on their Nortons and later BMWs. The old-school DRLs Stopped at Traffic lights in a French City and an armed Policeman walked over and tapped my Motorbikes's Headlamp,looked at him and he said 'ON',end of conversation. That occurred way back in the Seventies,in broad Daylight. CT Link to comment Share on other sites More sharing options...
Guest Posted January 26, 2017 Report Share Posted January 26, 2017 Stopped at Traffic lights in a French City and an armed Policeman walked over and tapped my Motorbikes's Headlamp,looked at him and he said 'ON',end of conversation. That occurred way back in the Seventies,in broad Daylight. CT Probably acetylene lamps then? Link to comment Share on other sites More sharing options...
cuthound Posted January 26, 2017 Report Share Posted January 26, 2017 (edited) I first came across daytime running lights in Scandinavia in the late 70's. The Swedes told me it was to prevent accidents where drivers going into a low sun failed to see someone coming the other way. My pet hate is auto dipping headlights. The problem is they only dip when presented with an oncoming light, so always dip a fraction of a second too late. Edited to remove autowrong induced gobbledygook. Edited January 26, 2017 by cuthound Link to comment Share on other sites More sharing options...
mross Posted January 26, 2017 Report Share Posted January 26, 2017 I can remember, as a lad, walking in Wales on a moonless night. With only starlight it was still possible to see where you were going - just. Link to comment Share on other sites More sharing options...
WotEver Posted January 26, 2017 Report Share Posted January 26, 2017 (edited) . Edited January 26, 2017 by WotEver Link to comment Share on other sites More sharing options...
mross Posted January 26, 2017 Report Share Posted January 26, 2017 Batteries called PP1 up to PP11 were available but there was never a PP2 ! Link to comment Share on other sites More sharing options...
Guest Posted January 26, 2017 Report Share Posted January 26, 2017 Batteries called PP1 up to PP11 were available but there was never a PP2 ! Could you create a PP2 by using 2x PP1 in parallel? Link to comment Share on other sites More sharing options...
cereal tiller Posted January 26, 2017 Report Share Posted January 26, 2017 Probably acetylene lamps then? No,had sold the Triumph by that time,this was a bit later when I owned a Honda CB750,Looxury! CT Link to comment Share on other sites More sharing options...
Guest Posted January 26, 2017 Report Share Posted January 26, 2017 No,had sold the Triumph by that time,this was a bit later when I owned a Honda CB750,Looxury! CT Lovely bike I had a CB400/4 for a number of years which I fitted a Yoshimura big bore kit, cam, gas flow etc. T'was a bit quicker than standard I really liked the Honda 4's in general, though always had a soft spot for the Honda CB500 twin. Never owned one though, but had a Yammy XS650 twin for a few years. Link to comment Share on other sites More sharing options...
Dave_P Posted January 26, 2017 Report Share Posted January 26, 2017 My front bike light is around 200 lumens, for pitch dark towpath it is just okay. 400 would be better. I find my 80 lumen light rather brighter than I need for the towpath and wish there was a way to turn it down. Link to comment Share on other sites More sharing options...
MtB Posted January 26, 2017 Report Share Posted January 26, 2017 Are lumens a logarithmic measurement rather like decibels? I.e is 400 lumens just a bit brighter than 200, or is 400 actually twice as bright as 200? Link to comment Share on other sites More sharing options...
ditchcrawler Posted January 26, 2017 Report Share Posted January 26, 2017 I can remember, as a lad, walking in Wales on a moonless night. With only starlight it was still possible to see where you were going - just. I very really used my torch when walking my dogs round the village at night. once you get away from the lights you can normally see quite well until someone comes along and blinds you. Link to comment Share on other sites More sharing options...
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