How does w/nm/m^2 relate to klux?

Bharath Patil

Intellectual 2030 points

Other Parts Discussed in Thread: OPT8241

In the system estimator, we see w/nm/m^2 as the unit for ambient light. How does it relate to klux of light intensity?

over 10 years ago

0 Bharath Patil over 10 years ago

TI__Intellectual 2030 points

Strictly speaking w/nm/m^2 is unrelated to klux at around the wavelengths that OPT8241 is sensitive to. This is because klux indicates the brightness from a human eye perspective and NIR (850nm) light is not visible to the human eye at all. Some light sources can have 1 million lux of light with close to zero emissions around 850nm.

Klux can be converted to w/nm/m^2 only for a given source of light with a known spectrum. For example, for sunlight, 100Klux maps to about 1W/nm/m^2 at 850nm.

Regards

0 Jason Bridgmon over 10 years ago in reply to Bharath Patil

TI__Genius 14825 points

This is an excellent discussion on the difference between photometric and radiometric units!

0 Bharath Patil over 10 years ago in reply to Jason Bridgmon

TI__Intellectual 2030 points

Thanks for the terminology

Photometric : Lux

Radiometric : W/nm/m^2

Regards

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How does w/nm/m^2 relate to klux?