Unreasonably Bright Bike Light Apparently Hunts Deer


[Jukka] wanted a bike light that wasn’t afraid to go into the woods during the dark winter. He put together a lamp that uses eight 3 Watt LEDs to pump out 1680 lumens (english translation). The high power LEDs were mounted on a large aluminum heat sink and use lenses to optimize the beam of light. The system uses a 2 amp driver board that he assembled himself. Power is provided by sixteen AA Nickel Metal Hydride batteries that are housed along with the driver circuit in a water bottle.

This more than doubles the output of the last bike light we thought was too bright. Where will this lumen-arms-race stop?

[Thanks Sami]

79 thoughts on “Unreasonably Bright Bike Light Apparently Hunts Deer

  1. He uses 0.9A with the current batteries as otherwise they run out too fast. This way he gets 1.5h. The full power is 2A and he just mentions that better lithium batteries should be used then instead of the nimh cells in use now.

  2. Actually the maker doesn’t mention anything about hunting. He just notes that eyes of animals and reflectors shine back from hundreds of meters away as shiny spots and that many animals let you get close because they dont seem to see the people behind the light, they just stop to wonder the bright light.

  3. @James: you can’t look to your side because most led lights use spots – it looks brighter and it’s also cheaper, because one can use flashlight reflectors.

    for a flashlight most people don’t want spill but a crisp spot, but for a (road-use) light, you want some side spill and not a sharp cutoff line that creates darkness (except for the top).
    add a lens with a horizontal beam to it, or if you have multiple leds, replace one.

  4. @courtney, @daddystop:
    see my comment @rob and the link i posted http://www.led-treiber.de/html/dynamo-treiber.html#LED-Standlicht
    bottle dynamos (afixed to the fork, with a little plastic wheel riding at the rim of your wheel) are cheap in europe, but i’ve seen them even in the u.s. for under $10.

    usually, they are looked down upon, because they usually power a dim 2.4 watt halogen bulb, that goes off as soon as you stop and constantly flickers.
    with leds, it is a different story, the guy above claims 3 leds in series with 200-250mA. that would be about 150 lumen for the front light without any battery! he also added some caps so you can stop without the light turning off.

    other people claim at least 3w: http://www.pilom.com/BicycleElectronics/Dynamo.htm
    his homepage has some interesting generator projects: http://www.pilom.com/BicycleElectronics/BicycleElectronics.htm

    and if you’ve never seen a bottle dynamo: http://en.wikipedia.org/wiki/Bottle_dynamo

  5. 1.) The new Prius has optional LED headlights, joining the ranks of the Escalade Premium and Audi R8.

    2.) Optics for Cree and Philips LEDs can be found on ledsupply.com or futureelectronics.com.

    3.) From the picture, it appears that only the blue hue spot is from the LED headlight. The intense light directly in front of the bike is NOT from the LEDs.

    4.) Anyone else severely scared of how he wired the LEDs? There is no protection from the leads shorting on the heatsink… Not that it really matters THAT much, as a short to ground just means the LEDs after the short go out. But, mounted on a bike for offroad travel, I’d personally insulate the connections.

  6. @tantris – that’s not the sole reason, many bike lights (LED and otherwise) use floods and they give the same effect. The reason being the white light bleaches your rod cells in your eyes (those used for low light vision) meaning anything below a certain intensity (outside your beam pattern) is effectively just black. If you use a wavelength that doesn’t bleach your rods you can have high intensity light in the spot or flood beam AND maintain low light vision for the out-of-beam areas.

    I spent a while riding around with high brightness blue LEDs (similar effect to reds – little bleaching of your night vision) and I could see a nicely illuminatd trail AND everything to the side, and when I turned the light off I could still ride by moonlight immediately. This is impossible with even my 90 degree flood halogens.

    It’s just a thought I’m playing with at the moment, but it seems to be holding true with a few tests, and it’s used in areas like naval warfare so I’m fairly sure it’s pretty accurate. I’ve talked it over with a couple of Profs in the field. I think the reason peope dont like it is that people like natural light colours (white) and red at the front is counter-intuitive on a vehicle :-)

  7. @emmaarmstrong – shoot, now i need brights, lowbeam, and trail lights?
    but seriously, i read some debates on the effectiveness of different colors (blue vs red debate) and what i got out of it so far is this: rods are blue sensitive but not red sensitive,
    http://hyperphysics.phy-astr.gsu.edu/hbase/vision/bright.html#c4 you see a blue led trail light with your rods and a red light with your cones.
    so my understanding is: if you want a really bright trail light, make it as far red as possible, your cones will pick it up but it won’t spoil your rods. if you want some smaller illumination, make it blue, your rods will pick it up but it won’t saturate them as easily as an (almost)-full spectrum white phosphor led.
    unfortunately, i really don’t like having a bright red light on the front;)

  8. @jd- #4: now, that you mention it. ooops, i thought the green coating was insulation.
    i did like the thing built into a handlight however, and the driver is worth a look. i used the zetex zxld1360 before, he uses the maxim max16820. with the maxim, he has to use an external fet, but this way his current is also not limited by the chip. the maxim is also cheaper.

  9. @tantris – sorry, the post by emmaarmstrong was me, the troubles of shared computers and not watching when you click submit! but to answer your thoughts..

    Checkout http://www.georgehernandez.com/h/xzMisc/Color/Media/EyeSpectralAbsorption.png also, makes the differences a bit more obvious but…

    Yes, to some extent a smaller quantity of blue would indeed make sense, but for the fact that we have bugger all blue receptors (something like 2% of total, and mostly scattered all over the retina) makes focusing on things illuminated in blue-only light much more difficult than red-only apparently.

    Our main problem is that we can’t really control the levels of brightness, one second it might be reflecting off white limestone, the next off dark soil. Because of this we tend to prepare for the worst case (dark soil in a dark wood maybe) and so we just blast out a blue light to match that, but this “smaller” illumination (so as not to bleach the rods) needs to be carefully controlled, whereas red doesn’t and provides better focusing (or rather resolution) due to between 50 and 75% of your cones being red.

    Did any of that make sense? It’s 3AM here!

    Maybe a combination of red and lower intensity blue? Red is fairly odd to ride with. But either are theoretically better than white. Worth a test, if you get spare time/LEDs. I’m currently tracking down some 3W reds and blues to test them both out.

  10. Also bear in mind that rods are not really found around the your main focus point, so illuminating with blue would mean you’d get fairly good peripheral vision with the rods but your blue cones would not be excited very much and so you’d lose low-light definition?

  11. In some countries it is indeed not allowed to have superbright light on bicycles, or lights with certain colors, but even if it is there are also many places where disturbing animals from their nightcycle and scaring them will be illegal.

    And I’m a bit on the fence, I’m disappointed that you apparently need such laws with idiots that pull stunts like this, but on the other hand I don’t like too many rules and I think even the maker of this would run around all night with these lights, it’s more a bragging thing to show on sites surely? In which case it’s OK I’d say, you just dont’ want tons of people actually using this kind of thing, in fact when a certain kind of xenon or something standard bicycle light became popular in my area I was already annoyed as hell at being blinded all the time, the damn things also were predominantly pointed up rather than down for some reason.

  12. @james: so, for the trail light a bright red spot in front of you and blue sidespill?
    but i doubt, that i will build that anytime soon. i have an unfinished road-compatible white led light, and that has priority.

    if anyone needs more reflector links: for the bar shaped part i’m thinking of either this one http://dealextreme.com/details.dx/sku.1919 or that one http://kaidomain.com/ProductDetails.aspx?ProductId=1788
    i got both, they are o.k. i glued reflective aluminum tape to the back of the glass reflector, which helped with wasted back spill and made them somehow “softer”.

  13. @ Wwhat

    The BMW Xenons have an auto-leveling system which directs the headlights down when the suspension angle changes so you don’t blind other drivers. They’ve been doing this since ’97 and it’s really nothing more than a fixed lever arm which signals a servo motor. Perhaps something that could be added to this to keep from blinding others and the added benefit of having light stay where you’re biking, even over uneven terrain…

  14. Sure bright, but overkill IMHO.

    My homebuilt E-bike light has just three Luxeon III LEDs, but I’ll bet it beats this one for ‘throw’, yet gives plenty of close range light too. 50mm dia. 2 degree Carclo optic (apparently no longer made) for long range (Up to about 100 yards /meters), and two 20 mm dia 25X6 degree elliptical optics for spread and close to medium range. Each LED can be used independently depending upon conditions / power conservation. With all three running, about equivalent to a single halogen car headlight on ‘bright’, but only requires 15-18 watts for maximum brightness.

    Next one I build will use Cree or Seoul Semiconductor LEDS for greater lumen per watt efficiency, although unfortunately that wonderful Carclo 2 degree optic isn’t quite compatible with the Crees or SSes. May have to experiment with aspeheric lenses to get that long ‘throw’.

  15. @Wwhat – These lights are great for night riding off-road, they’re never designed to be used on-road. Certainly nowhere in the UK is it illegal to disturb animals overnight, and we don’t really have many to disturb. For that matter, the number of night-riding MTBers are VERY low – it’s hardly a massive problem. HIDs are used as a fairly “normal” light for night riding currently, and are similarly bright to this.

    I’m not sure why you find it such a problem to be honest – if it’s on road then the rider is being stupid using high-brightness lights on the road (though some would say it’s about the only way of getting drivers to realise you’re there) and in the woods there are bugger all people about and no-one to upset.

  16. Mounting the LEDs in an arc left to right may give on a pattern. 2 rows may give you an eccentrically switched high beam or low beam. I do suspect even with this light you aren’t going to see that tree that’s about to cut your face. Imagine this light when there’s snow cover, useless, unless the contoller/power supply can reduce the output. Speaking of the controller it would be nice to be able to see the pdf file associated with that.

  17. To the people talking about LED car headlights, there’s plenty of cars with LED rear lights, and some with LED sidelights, but only the Audi R8 has LED headlights. Although there’s many with bi-xenon as standard or an option.

  18. 1680 lumen? it’s too damn bright,how about 400watt metal halide that puts out 35000 lumen ,going to do some modification on my bike to fit that lamp,powered by 2 car batteries ,it’ll be awesome

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