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  1. #1
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    Apparently, Not All Lumens Are Created Equal

    So I recently mounted a Fenix L1D flashlight (LED) on my helmet to supplement the Light & Motion Solo Logic (halogen) on my handlebars. I find it amazing that the flashlight set to medium (53 lumens) lights up the road much better than the Solo on low (120 lumens). The same goes with the other power settings. It takes far fewer LED lumens (1/2 or 1/3 maybe) to equal the same useful lighting from the halogen. I guess it's the whiter light??

    I've been wanting a brighter main light (solo logic on high is 390 lumens) and figured I needed around 800 lumens, but now I think a 400 lumen LED light would suffice.

    From now on I will always rock the handlebar/helmet light combo. The helmet light is soooo useful.

  2. #2
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    I draw a distinction between "lighting up the road" and discernible visibility. I always had a halogen light (Marwi Nightpro Torch 15 watt), but I recently purchased a Cygolite Li-ion Dual Cross and love all the advantages of the LED.....including the extremely white light of the Dual Cross. It lights up the road much more intensely than the halogen (and feel I am seen by others better as well).....I would never go back now. But as far as distinguishing detail on and around the roadway surfaces, I miss the yellower light of my old Nightpro.

  3. #3
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    It's possible that the Fenix is more concentrated. Since lumens is overall light output, if the Fenix produces a more concentrated beam, it may seem brighter since you're typically looking at where you're pointing. I personally prefer a more spread-out beam that gives me a feel of the surroundings.
    Same roads, same rights, same rules.
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  4. #4
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    Forget medium or even high on the FENIX. Get 2 x AA L2D, 2700mA batts and go TURBO all the way - it's awesome!
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    Cervelo P2C Dura-Ace 2008

  5. #5
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    Turbo is indeed the best, and since the bike is moving, it won't overheat.

  6. #6
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    It's turbo time.
    "I was racing after him at 55 km/h, and he took a minute off me."
    ---Boonen on Cancellara with 15 km to go at Flanders 2010

  7. #7
    Zoom zoom zoom zoom bonk znomit's Avatar
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    400lm is fine for road, 200 is ok most of the time....as long as its in a good beam.
    You make your beam 2x as wide then its only 1/4 as bright.
    Fenix looks super bright but gives a small spot...great if you travel in straight lines.

    Halogen lumens are very voltage/bulb dependant, hard to get reliable numbers.

  8. #8
    Recreational rider
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    I just wish there was a more uniform way for light manufacturers to report the specs. Ideally it would be something like this:

    1) Power consumption in milliwatts
    2) Beam shape and projection, i.e. round 1:8 meaning circular beam, 1" diameter for every 8" from source
    3) Total visible lumens output (important since various technologies have different lm/watt)

    From that, it would tell you just about everything you need to know. You could calculate the runtime on whatever battery you're using, the brightness at whatever range you're using it at, and the brightness, which honestly would be to help to decide if the width is sufficient at the range at which the brightness would be sufficient. Ahh, the things that would be so great in a perfect world.

  9. #9
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    Quote Originally Posted by agarose2000 View Post
    Forget medium or even high on the FENIX. Get 2 x AA L2D, 2700mA batts and go TURBO all the way - it's awesome!
    For my helmet I wanted something small. The L1D is very compact and I find that even on the 53 lumen setting it's plenty to light up street signs, see around corners, and flash drivers. A couple L2Ds on the handlebars would be nice , but a pain to pull the batteries out to recharge daily (I ride 2 hrs per day).

    The beam patterns of the Fenix and the L&M seem very similar. Both have a bright spot with moderate flood, though the L&M can be adjusted to reduce the spot.

  10. #10
    World's slowest cyclist.
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    Your experience shows the importance of optics. It's not the lumens that matter, it's where you put them. The only lumens that count are the ones that fall on the stuff you want to see.

  11. #11
    Gears? CliftonGK1's Avatar
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    The difference you're seeing is between power and intensity.

    Lumens = candela / steradian
    Lux = lumens / m^2

    Lux is an actual measure of intensity, like the candela.
    The lumen is a measure of percieved power.
    Last edited by CliftonGK1; 02-27-08 at 10:09 PM. Reason: correction to definitions
    "I feel like my world was classier before I found cyclocross."
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  12. #12
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    Quote Originally Posted by ellerbro View Post
    For my helmet I wanted something small. The L1D is very compact and I find that even on the 53 lumen setting it's plenty to light up street signs, see around corners, and flash drivers. A couple L2Ds on the handlebars would be nice , but a pain to pull the batteries out to recharge daily (I ride 2 hrs per day).

    The beam patterns of the Fenix and the L&M seem very similar. Both have a bright spot with moderate flood, though the L&M can be adjusted to reduce the spot.
    Nothing wrong with the excellent L1D, but I'd emphasize that the L2D is still very, very small, and very, very light. I wear it for running, which is much more sensitive to weight given the jolting nature of the movement compared to the smoother ride of a bicycle, and the weight of the L2d is completely negligible. LOVE the turbo mode - I've run for over 2.5 hours at night with it around LA, and it takes maybe 1 minute max to swap out the batteries to keep on truckin' again. I'd be hard pressed to find an easier battery loading system - the screwoff cap works well, and is far easier to deal with than the LED headlamps I used to fuss with.

    Recharging daily isn't a problem as well. I just throw 'em into the charger overnight the moment I get home, and voila - super runtime in the AM, and no worries that I'm underpowered in the middle of a run/ride.
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  13. #13
    Scott n4zou's Avatar
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    Quote Originally Posted by Chris_F View Post
    Your experience shows the importance of optics. It's not the lumens that matter, it's where you put them. The only lumens that count are the ones that fall on the stuff you want to see.
    +1
    I built my own dynamo LED headlight using a Seoul Z-Power U-BIN LED in a Fraen Elliptical Beam Lens With Holder. This setup lights up the road as well as a battery powered 15-Watt MR-16 halogen headlight. After experiencing freedom from batteries I'll never go back to using battery powered headlights.

    LED: http://www.dealextreme.com/details.dx/sku.1445



    Fraen lens with holder: http://www.luxeonstar.com/item.php?i...HS-HEB1-LL01-H


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