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Led lux

Discussion in 'Dive Rite' started by LGH, Oct 21, 2009.

  1. LGH

    LGH Angel Fish

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    Hello there,

    Could you please tell me what actual LED light sources are used in the LED LUX? The "Almost 1000 lumens" from the product page says pretty much nothing and is almost worthless for comparing to other lights.

    Also, the angle of the beam would be good information too.
     
  2. Dive Rite

    Dive Rite Dive Equipment Manufacturer

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    975 lumens, 12 degree angle.

    Thanks,
    Kathleen
     
  3. LGH

    LGH Angel Fish

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    Well, that was more of the same, really. :)

    Anyhow, for those interested, I dug up the info at the Candlepower forums: The LED LUX uses three Luxeon K2 LEDs.
     
  4. DA Aquamaster

    DA Aquamaster Directional Toast ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: NC
    11,202
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    113
    Actually her answer was pretty good.

    A lumen equals one foot candle of illumination over one square foot. If you know the lumens and the angle, you can figure the rest. And how much illumination you then have in any given square foot depends on the distance from the light to the subject.

    That tells me a lot more than "three Luxeon K2 LEDs" as to make any useful sense of that I need to see the specs for those LEDs and you didn't post them.

    The only thing her response lacked was the color temp of the light and that can be assumed to be pretty much in the white to slightly bluish white range common to most LED lights in that class.

    -----

    A "lux" is a lumen per square meter (so the name of the light implies 1000 lumens per square meter.) A circle with a diameter of 1.13 meters would have an area of 1 square meters. With a 12 degree angle, the beam will cover 1 square meter at a distance of about 5.3 meters, or about 17.3 feet. So if the name is correct, you would expect 1000 lumens of illumination over an area of 1 square meter at a distance of about 17.3 feet. Since it puts out 975 lumens, you get 975 lumens of illumination in a 1 meter circle at about 17.3 ft (minus what ever got absorbed by the water).

    What does that mean? A cloudy day has an illuminance of about 2000 to 10,000 lux. A dull heavy overcast day has an illuminance of 100 to 2000 lux.

    That sounds bad until you consider that the average office has about 200-300 lux and the average living room has 50-200 lux.

    Comparing to other lights is fine, but you need to be able to quantify it to something that is actually meaningful.

    Personally, I use a 700 LED when cave diving and it is plenty of light in most caves. In some of the bigger and darker walled systems (some parts of Manatee, etc) I find I could use a little more light and a little more penetration.
     
  5. LGH

    LGH Angel Fish

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    Thanks for the nice write-up!

    Still, I find numbers don't quite tell the whole story. If I know what a Luxeon K2 looks like in my diving conditions (poor visibility, greenish or red/brown waters) I can get a better idea if I know there are three of those LEDs in a lamp.

    How is the LED 700 in poor visibility?
     
  6. DA Aquamaster

    DA Aquamaster Directional Toast ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: NC
    11,202
    1,282
    113
    In poor visibility, I prefer my 10W HID. The very tight and intense hot spot in the MR11 head seems to do a little better than the LED 700 with less backscatter. But to be fair the LED 700 does a lot better than the LED 500 in poor viz (and I plan on having my 500 upgraded to a 700), so the LED Lux may be close to the 10W HID in poor viz.
     
  7. buddhasummer

    buddhasummer Divemaster

    # of Dives: 1,000 - 2,499
    Location:
    5,518
    928
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    I have the LED500 and will probably upgrade to the 700, do you know the beam angle of the LED500/700? Cheers
     
  8. cbrich

    cbrich Solo Diver

    # of Dives:
    Location: Austin
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    I would assume the beam angle is the same for all of the Dive Rite's LED lights using 3 LEDs.

    Sounds like someone is trying to copy the LUX light. Why? Just go out on a limb and build a light with 3 Cree MC-E LEDs. This setup will give you close to 3,000 lumens with a beam angle of 10*.

    Someday I will build a dive light that will produce about 7,000 lumens and have a burn time of 4 hours.
     
  9. Dive Rite

    Dive Rite Dive Equipment Manufacturer

    855
    64
    28
    12 degrees

    Kathleen
     
  10. buddhasummer

    buddhasummer Divemaster

    # of Dives: 1,000 - 2,499
    Location:
    5,518
    928
    113
    sorry just re read thread and you already answered this. Thanks
     

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