Inexpensive chip-based device may transform spectrometry

Re:Inexpensive chip-based device may transform spectrometry by danielvf on Friday October 26, 2018 @09:06AM (#18308791)

Summing RGB sensors doesn't really work the way you would think because each sensor is actually sensitive to a very broad range of wavelengths, some of which affect it more, and some of which affect it less. Unless you know what your red sensor reads with X amount of illumination at 635nm vs 670nm, you are going to get very bumpy results on even a blackbody.

There's still some of variation in colored LEDs. (and unless you are paying big bucks, a ton of variation on white LEDs. What most home LED bulb companies do is buy a bunch of off color white LEDs and sort them per light so that the badness sort of evens out to something close to okay.)

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Re:Inexpensive chip-based device may transform spectrometry by analog31 on Friday October 26, 2018 @06:00PM (#18313007)

Indeed, once the sensors are summed, the intensity scale of the spectrometer still needs to be calibrated using something like a blackbody source.

But even monochrome sensors have lumpy response.

I'm only suggesting to use colored LED's as crude wavelength references and a blackbody as an intensity versus wavelength reference, for something that's good enough for home experimentation within reason.

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