Thread: Helmet lights
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Old 12-02-12 | 10:43 AM
  #33  
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cyccommute
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Originally Posted by mikhalit
Jee, how can anyone ride with 1000+ lumens without being sorry for other people on the road? I've tried to look at my Magicshine from the distance during daytime and it's painful! Clearly, at night it makes people blind..

I do have a helmet light, simple Petzl Tikka, and it's enough to be seen. I also run a combination of focused dynamo light and a Magicshine, but usually i cover the latter with my palm when a car or anyone else appears in front... Something you can't do with a helmet light.
But you can lift your chin. Or turn your head. Or look down. The light is on a gimbal mount that has a wide range of movements.

Originally Posted by jputnam
It's not just the lumens, it's the beam pattern. Car headlights are in the 1,000-lumen range, but much less blinding than the typical bike headlight, because car headlight beam patterns are strictly regulated to keep the high-intensity part of the beam aimed down at the road, not up in the eyes of oncoming traffic.

Some bicycle headlights have reasonable beam patterns, but most use cheap round flashlight-style reflectors that throw at least half the light places it isn't useful.

Of course, helmet lights point the light where you're looking, so it's a bad idea to put a dazzlingly-powerful light on a helmet. But you don't need that bright a light to be seen by motorists. Put the powerful light on the bike where you can control its beam responsibly, and put a smaller light on the helmet for conspicuity.
You and mikhalit are both making a common argument that is based on mistaken observations about bike lights. First, yes, the beam is intense if you look at it directly. But, then, a car light is incredibly intense if you look directly into it. Go out and stand at arms length and eye level...which is how most people 'test' the brightness of bicycle lights...and have someone switch on the lights of your car. You'll be seeing blue spots for a week.

But a bicycle light is a lot of light packed into a pretty small space. That is both the problem with the 'hold the light at arms length, turn on the light and then complain about how bright it is' and the argument that the light is blinding to road users. Putting that much output into a small package with a small reflector concentrates the light into a narrow cone. When you consider where we cyclists ride, i.e. usually a few feet to the right of the passenger's light on a car, a narrow cone of light isn't going to shine into the eyes of on-coming traffic.

Originally Posted by jyl
I find the opposite. My helmet light is a narrow, spot beam. When I'm in normal riding position it points at the ground about 40 ft away. To light up a driver or a mirror, I have to lift my head. So the light is not in people's eyes, unless I want it to be.

The situation where my helmet light is too bright is on a dark path, especially where cyclists or pedestrians are coming toward me. I turn it off there. It is really meant for riding in traffic.
Exactly.
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