# How they measure Lumen and Lux of a headlamp



## michaelmuller (Mar 26, 2009)

A headlamp claimed to be 1300-Lumen, how they measure, and in what condition, and these 1300-lumen headlamp translate to how many Lux?


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## Shorty66 (Mar 26, 2009)

Lux is lumen per sqaremeter. This means, you need the lit up area to calcualte lumens out of lux or vice versa.

To precisely determine the output of a lamp in Lumen you need an integrating sphere.
Without integrating sphere it is rather difficult to measure the lumens correctly, because the lights do not have a uniform output in each direcion and you would have to take sidespill, hotspots and ringing or other artifacts into account.

Read wikipedia for further information.


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## Marduke (Mar 26, 2009)

michaelmuller said:


> A headlamp claimed to be 1300-Lumen, how they measure, and in what condition, and these 1300-lumen headlamp translate to how many Lux?



Lumens and lux are not directly related, and are in now way connected on a given light.

Also, I would be HIGHLY suspicious of a 1300 lumen headlamp. Perhaps they forgot a decimal.


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## michaelmuller (Mar 26, 2009)

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10-02-2007, 08:46 PM 


mulki




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*Worlds brightest Bicycle light - 1400 lumens* 
Just saw this on Gizmodo:













The article says that it uses "7 high quality LEDs". No mention of type of LEDs used.

Cost $ 1185. 

Edit - Forgot the article link: 
http://gizmodo.com/gadgets/super-cyc...tty-305959.php 
_Last edited by mulki; 10-02-2007 at 08:50 PM. Reason: Added Link to article. _


 

 

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10-02-2007, 09:09 PM 


Szemhazai




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Join Date: Jan 2006
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*Re: Worlds brightest Bicycle light - 1400 lumens* 
Read the archive... It’s Lupine Betty 6/12 not 1400 lumens – they take this value from SSC datasheet - but about 1100 lumens . So still the “brightest” is CayEye Stadium 3 – proved for about 1600 lumen power HID if I remember correctly... 
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