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I didn't realize we even had a discrete LED tunable across the visible spectrum, let alone a Micro-LED array of them. Anybody know where I can buy one? I want t

I didn't realize we even had a discrete LED tunable across the visible spectrum, let alone a Micro-LED array of them. Anybody know where I can buy one? I want to build a hyperspectral imager.

jessriedel 2y ago
Do you mean hyperspectral imager (i.e., camera), or a hyperspectral display?
- FriedPickles 2y ago
  An imager/camera: by illuminating a scene (or light box) solely with the tunable LED, sweeping it across the spectrum, and capturing it with an achromatic camera.
  - jessriedel 2y ago
    Ahh, that makes sense. Thanks! Btw, is that still reasonably effective if the scene has ambient illumination, but (in addition to shining each wavelength at it) you take a monochrome photo in only the ambient light and you subtract that out from all your other images?
    - FriedPickles 2y ago
      Sure that would work. The higher the ratio of controlled/ambient light, and the slower you can do the sweep, the better for SNR of the hyperspectral image.
  - lsaferite 2y ago
    > achromatic camera Is that the same as a panchromatic camera? Edit: Asking because I have a 410x410px hyperspectral imager that has an aligned 1886x1886px panchromatic imager that is use to perform pan-sharpening of the HSI data bringing it up to 1886x1886. I'd never heard of a panchromatic camera before I got involved in this business and I've never heard of an achromatic camera either. All I seem to find is achromatic lenses.
    - FriedPickles 2y ago
      Yes, "panchromatic" is probably the more accurate term for it. It's just a camera with no color filters and a known spectral response curve that's high enough across the frequencies being imaged.
      - lsaferite 2y ago
        Ah, yeah, I'd say that fits 'panchromatic camera' then. The panchromatic imager on my setup uses the exact same CCD and covers the exact same spectral range (350nm-1000nm), but it doesn't have the HSI lenses/filters. The company actually sells a smaller unit that is made from the same imager, but with the HS lens/filters.

I didn't realize we even had a discrete LED tunable across the visible spectrum, let alone a Micro-LED array of them. Anybody know where I can buy one? I want to build a hyperspectral imager.

jessriedel 2y ago

Do you mean hyperspectral imager (i.e., camera), or a hyperspectral display?

FriedPickles 2y ago
An imager/camera: by illuminating a scene (or light box) solely with the tunable LED, sweeping it across the spectrum, and capturing it with an achromatic camera.
- jessriedel 2y ago
  Ahh, that makes sense. Thanks! Btw, is that still reasonably effective if the scene has ambient illumination, but (in addition to shining each wavelength at it) you take a monochrome photo in only the ambient light and you subtract that out from all your other images?
  - FriedPickles 2y ago
    Sure that would work. The higher the ratio of controlled/ambient light, and the slower you can do the sweep, the better for SNR of the hyperspectral image.
- lsaferite 2y ago
  > achromatic camera Is that the same as a panchromatic camera? Edit: Asking because I have a 410x410px hyperspectral imager that has an aligned 1886x1886px panchromatic imager that is use to perform pan-sharpening of the HSI data bringing it up to 1886x1886. I'd never heard of a panchromatic camera before I got involved in this business and I've never heard of an achromatic camera either. All I seem to find is achromatic lenses.
  - FriedPickles 2y ago
    Yes, "panchromatic" is probably the more accurate term for it. It's just a camera with no color filters and a known spectral response curve that's high enough across the frequencies being imaged.
    - lsaferite 2y ago
      Ah, yeah, I'd say that fits 'panchromatic camera' then. The panchromatic imager on my setup uses the exact same CCD and covers the exact same spectral range (350nm-1000nm), but it doesn't have the HSI lenses/filters. The company actually sells a smaller unit that is made from the same imager, but with the HS lens/filters.