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> Rather than taking a photograph, satellite sensors record electromagnetic radiation in the red, blue, green, and high-resolution panchromatic (black-and-white
by Phrodo_00 5y ago
> Rather than taking a photograph, satellite sensors record electromagnetic radiation in the red, blue, green, and high-resolution panchromatic (black-and-white) bands (as well as several not visible to the human eye, as this Mapbox[2] post helpfully explains). When these bands are combined to produce a visible image
That's the same as taking a (normal, digital) photograph (sans additional non-rgb layers), just explained.
- ihattendorf 5y agoThe difference is typical digital cameras have a bayer filter in front of the sensor to allow taking a single color picture vs. here it sounds like multiple captures with individual filters (e.g. 1 blue, 1 red, 1 green, 1 monochrome) that are later combined into a color picture.
- wodenokoto 5y agoThe point was at all color photos record electromagnetic radiation in visible colors. The “it doesn’t take photos it record electromagnetic radiation” is a silly thing to say.
- daniel_reetz 5y agoThere's some subtlety here. Colors are percepts- phenomena that happen in the brain. Wavelengths and radiation describe natural electromagnetic phenomena, not percepts. Example: Infrared has no "color". It's possible to induce the illusion of colors in the absence of light altogether. I appreciate that the article took care with this language, as it's a deep and fascinating topic.
- s1artibartfast 5y agoThis could be a comparative description of digital vs Chemical photography
- wodenokoto 5y agoBoth are still capturing light.
- nkmnz 5y ago"Chemical" photography captures electromagnetic radiation as well, but converts it into bonding energy, not into electrical signals.