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Thread: LED-How to tell the real ligthing output of led lights?How to compare lighting power?

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    LED-How to tell the real ligthing output of led lights?How to compare lighting power?

    I am looking at several led light options. Obviously, one of the considerations is how much light the led panel emits.
    Some companies list their products specifying out put via "lux"
    Flashpoint 500C LED Light - Works on AC or V Mount Battery - Bi-Color 500LEDBBB
    Others list Watt, W.
    ID508-v2: ID508-v2 LED Studio Light w/Light Stand Mount
    Others use lumens...

    My questions: How to measure/compare the lighting output of led lights? Is there a way to convert these numbers? All I want to know how much light these lights output so I can compare them.

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    Re: LED-How to tell the real ligthing output of led lights?How to compare lighting po

    conversion tables here http://www.rapidtables.com/calc/ligh...calculator.htm

    explanation of terminology here http://www.greenbusinesslight.com/pa...mens-and-watts

    hth

    Best wishes,
    Ray

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    Re: LED-How to tell the real ligthing output of led lights?How to compare lighting po

    not that simple.

    lux will tell you how much light you get at a distance, usually along the centre axis of the beam.
    this means that if you have a spot light or if you have a wide beam the value will be the same despite the coverage being different.


    lumens will tell the amount of light coming out of the fixture. But lumen alone will not tell you the distribution, so you will not be able to guess the lux level at a distance unless....

    you have the intensity curve. The intensity curve is the only way that you have to determine the light distribution. often this is scaled by a 1000lm factor

    unfortunately this data is not available for most of consumer (and even pro) products.


    and even more depressingly the colour quality of the light are often unknown. if you have a colour rendering of 90, you may be quite disappointed by the rendition of the reds. A full set of colour rendition for each R sample should be considered...
    etc.


    g.

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    Re: LED-How to tell the real ligthing output of led lights?How to compare lighting po

    Quote Originally Posted by geotrupes View Post
    not that simple.

    lux will tell you how much light you get at a distance, usually along the centre axis of the beam.
    this means that if you have a spot light or if you have a wide beam the value will be the same despite the coverage being different.


    lumens will tell the amount of light coming out of the fixture. But lumen alone will not tell you the distribution, so you will not be able to guess the lux level at a distance unless....

    you have the intensity curve. The intensity curve is the only way that you have to determine the light distribution. often this is scaled by a 1000lm factor

    unfortunately this data is not available for most of consumer (and even pro) products.


    and even more depressingly the colour quality of the light are often unknown. if you have a colour rendering of 90, you may be quite disappointed by the rendition of the reds. A full set of colour rendition for each R sample should be considered...
    etc.


    g.
    I was going to drop a similar post--really isn't as simple as that.

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