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Convert Wavelength (nm) to RGB & HEX - Online Calculator






Nice, could be used for "accurate" font colors for the lasers in the signature :D
 
I was using a program that do it: can't remember his name tho.
Good find ;) thx.
 
There's a wavelength to RGB executable that I saw somewhere too, but I figured that a web-based calculator would be more convenient in some situations (cross platform, works on phones etc) Enjoy!
 
(I just added a completely superfluous live updating visualization of the wavelength lookup history - I reset the history too, so the first person to search a wavelength will hold the huge honor of triggering the first visualized bar!)
 
You might need to modify the algorithm a bit to make it accurate in near-UV and near-IR.

I had to in order to get satisfactory results on my label generator. :)

-Trevor
 
It does factor in a falloff multiplier near the edges, but I may need to double check that it's producing good results. Love your signature visualization!

Actually, it looks like I left that off the visualization. Though it's still in the rgb and hex calc, just not the bar chart eye candy. Will fix in the morning :)
 
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Uhm ..... that algorythm ..... can just take input from a text field, or also from a video device ? (camera or linear sensor, as example)

I know my ideas are usually crazy, but ..... you know ? :eg: the first thing that come me in mind, hearing "wavelenght/RGB conversion" words, is the opposite ..... that turns in "cheap PC spectrophotometer" :p :D ..... so, if that can be turned in a standalone PC application .....

I mean, i can imagine easily a phisical setup for hook a slit, a serie of lenses and mirrors, a diffraction device (prism or grating, don't count, they have different optical characteristics that must be corrected in the program or with the inclination of the CCD, anyway), to a webcam USB-based CCD or CMOS video device (or, also better, to a linear CCD device, that have more reading elements and more large reading field), instead to use them as a simple monochromator ..... all the hardware part is relatively easy to build, after all.

But, at this point, i need a software that can acquire the image from the cam (no matter the speed, it can also just be one frame per second :p), or acquire the data stream from the linear CCD sensor, if this is used, get the different intensities from the reading zone of the image, apply the correction curve (a compensation curve that is the exact opposite of the sensitivity curve of the CCD or CMOS sensor used, so this make the output reading curve a "flat response" curve for all the wavelenghts), measure the intensity curve and display it ..... and in programming field, my "skill" suck a little bit.

Anyway, i'm asking cause a similar setup can be done, basically in 2 different ways ..... or using a diffraction setup with a linear sensor, that gives you a spectrm reading based on the different intensities of a line (precise, but require a decent potomechanical setup) ..... or a CCD / CMOS sensor, where the light can be directly read as RGBI data, and converted from a specific software (much less precise, but also much more cheap, and this setup can also be used for a beam profiler)
 
@HIMNL9
It is perfecly possible (with IR filter). Try it, take a picture of a weak 1mw reddie shining direcly on your ccd with all lights off, use ColorCop and take a RGB reading of the picture. After, try the site with 660nm and see the results matches ;)
I would do it but I don't have neither reddie, neither camera. :beer:
 
Something to keep in mind -
Not every RGB / HEX value will have a corresponding wavelength.
 
it is worth a try, isn't it? I think that all RGB values have a corresponding wavelength. Dunno if the site supports float numbers ;);)
 
Yeah, i know rhd, mine was a "cheap for hobbysts" idea ..... also, Leodanshan, that program gives you the RGB values fr any single pixel choosen from the tool, but you need the opposite, for get a working spectrometer.

There are basically two ways, as far as i can imagine ..... the first one is the cheaper one, take the image of the dot in a camera (taking away the lens and placing a ND filter in front of the CCD sensor), you can get the image and convert the colors in wavelenghts (with the above limitation), and also get a cheap beam profiler .....

The second way, much more precise, but it require some DIY works in optical and mechanical fields, is to pass the light through a slit, then diffract it with a prism or diffraction grating, then project it on a linear CCD sensor, reading the "stream" of data at the output as the spectrum ..... i already made some experiments in this sense, but the output i had, was just shown on an oscilloscope as a "spectrum analyzer" graph, no PC interface nor plotting/recording capability ..... i was wondering if there's a way for read the output of the linear CCD as a data stream from a simple PC interface and manage it for convert it in a graph with reading possibilities, without have to use already-made units (they already exists, but they are not cheap for sure :p)

Sort of "pseudo-monochromator", but without the motor, encoder and mobile grating, a direct-reading unit.

Isn't it weird enough, as idea ? *insert evil laugh here*
 
I'll work on an algorithm. :D

It'd at least be an interesting image processing project.

-Trevor
 
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@HIMNL9
Just go lowering the number until you get what you want..

edit: you can call me Leo, pls. :beer:
 
They definitely don't.

For example, THIS COLOUR doesn't have a wavelength. Nor does THIS or THIS, yet those are, of course, HEX/RGB values.

The other challenge you might run into would be the accuracy of a web camera, and you would certainly, if nothing else, need the capability of disabling auto-white-balance.
 
combined HEX values.

Actually they have a wavelength because light is emitted in waves so, if it is visible, it has a wavelength (or more). :D
 
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