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Thursday, May 5, 2011

VIDEO: Lumen Logic—inside BD lighting technology

Lumens are an excellent way to gain a grasp of the total light output of each of our headlamps. Watch this video to learn how we measure lumens and what lumen rating is best for you and your adventures.

 

Recent Talk (1)

  • Brian
    1 Dec 2010, 12:06PM

    I do a lot of mountain backpacking with alpine starts and late night finishes. I've got an Icon headlamp (very new), which is fine with freshly charged or new batteries, but becomes noticeably dimmer even on lower power settings. Even two hours of hiking makes a noticeable and frustrating difference. My wife has a competitor's light that stays consistently bright right up to until the time the batteries need to be changed. When I asked the guys at REI about the issue, they said this was because my wife's light uses a regulated output, while the BD Icon's is not. As a result, I have found myself having to change out batteries somewhat frequently to keep a level of output that I need and now have a collection of half-charged disposable batteries. A couple of friends, one with the same BD light (Icon) have the same issue with the light tapering off.

    All this being said, there are two questions I have:
    1. Does BD have any intent to put this regulated output into the design of the Icon, or upcoming similar lamp?
    2. Instead of simply providing details on a new bulb when measuring output, maybe you can provide some better tests that demonstrate how the lights will perform during actual use, as the power in the batteries start to diminish.

    Comments would be welcome!

  • Qing
    27 Sep 2010, 3:20AM

    Hi, i have some questions about the headlamp tests. For new SPOT,370 TESTS IN AN INTEGRATING SPHERE,what does the sphere mean? And,
    NEGATIVE 29C EXTREME-COLD DROP TESTS, the DROP is a real drop, or the performance during the temperature drop?

    thanks

  • Kyle
    21 Sep 2010, 11:18PM

    Good information here, thank you. I like the direction to refer to lumens instead of wattage. For reference, how do SinglePower, DoublePower etc.compare to 1watt, 2 watt, etc? How do the 1watt of my old Spot headlamp and the DoublePower of the new Spot compare? It looks like a great new design, and I love the inclusion of red LEDs. I'd hate to lose the versatility of Spot by sacrificing too many lumens though.
    Also, feedback for potential website clarification, the first bullet of the Spot S11 description seems to say the output is 75 lumens for all 5 LEDs on at once, at max output. Is this right? It seems a rare circumstance one would use that setting. It might be more useful to list the lumens for each setting sepparately. For what its worth.
    Thanks for your time and for great products!

  • BD crew
    20 Sep 2010, 11:34AM

    Sandy -- To measure the distance we use a light meter with a 25 MM receiver. It measures the light in “lux”. The test equipment we use is the same test equipment used in the labs at our biggest retailers.

  • Sandy
    15 Sep 2010, 8:44AM

    What equipment do you use to measure the distance?

  • Scott
    9 Apr 2010, 12:55PM

    For the BD Ion Headlamp, what is the lumen output on low?

    As a backpacker, the Ion's small size and light weight are appealing. I own several of the 1st version. I carry one for camp chores: cooking, setting up sleeping quarters, watering the rocks. 3 to 5 lumens is enough, but run time is important. 20 to 30 hr at 35F would be nice. For your next version of the Ion, please consider a low low and using a CR2 battery, both for longer run time.

  • BD crew
    30 Mar 2010, 1:31PM

    Actually, we do use a lux measurement and that information is critical to us when designing the optical components in our headlamps and lanterns. Our distance measurements are calculated by determining the maximum "lux" level at two meters. We then use the Inverse Proportion law (rule) to extrapolate the distance the light beam will provide a 0.25 lux measurement. This 0.25 lux is the equivalent of the amount of light that is produced by a full moon on a clear night, which is a light level most people have experienced. The distance measurements and the manner in which we calculate them are the standard followed by all major headlamp and lantern manufacturers. Black Diamond also calculates battery life (burntime) by running the headlamp or lantern until a light level of 0.25 lux at two meters is reached.

    If you really care, here is the math for distance calculation:

    E=i/(D2). [The D2 is D "squared" but we can't do superscripts in the comments, so sorry for any confusion!]

    E is the illuminance in "lux", “i” is the luminous intensity (in candela) and D is the distance in meters, from which the measurement was taken.

    We measure an Icon headlamp to read 651 lux at 2 meters. Therefore the luminous intensity is: 651=i/(22) or i=651 x 4 = 2604 candela. [Again, the i/(22) is actually 2 squared]

    To calculate the distance the light beam will read 0.25 lux, we substitute these values into the equation:
    0.25 = 2604 / D2 or D2 = 2604 / 0.25 or D = (10,416)-2 D = 102.05 meters. [One more time, D2 is D squared]

    There will a quiz on this tomorrow.

  • Johnny
    30 Mar 2010, 4:42AM

    Why don't use "Lux" in the measurement?
    Of course, we want to know how much light come from the product, but we need to consider the light beam and angle, right? The main purpose of light is for our work (eg. ski, climbing, mountaineering...etc.) I believe that "Lux" can show us the effectiveness of light for our use.

  • Mark
    18 Mar 2010, 7:15PM

    Very informative and fun to see behind the scenes - thanks BD!

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