alt Hacker NewsThat is far-IR, thermal stuff, Near-IR, 700 nanometer-ish is right below red in human vision.
Camera sensors can pick up a little near-IR so they have have a filter to block it. If that filter was removed and a filter to block visable light was used in place you would have a camera that can only see non-visable light. Poorly, the camera was not engineered to operate in this bandwidth, but it might be good enough for a mask. A mask that does not interfere with any visible colors.
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throwway120385 • yesterday at 9:38 PM
You can actually dimly perceive near-IR LEDs -- they'll glow slightly red in darkness.
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> Poorly, the camera was not engineered to operate in this bandwidth
At least for cheap sensors in phones and security cameras that engineering consists of installing an IR filter. They pick it up just fine but we often don't want them to.
Keep in mind that sensors are inherently monochrome. They use multiple input pixels per output pixel with various filters in order to determine information about color.