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Fluorescent tubes flicker at 100/120 Hz, but the flicker is less pronounced because the phosphor keeps giving off light for some time after the electrical current stops flowing.

White tubes are made of a mixture of phosphors, and each of them has a different time constant, meaning the flickering is noticeable as repeated changing of colors. Take a photograph (with a rolling shutter phone for example) of a fast moving object under fluorescent light and you'll see blue and yellow shadows from the changing light[1].

[1]: https://photo.stackexchange.com/questions/60701/why-do-i-get...



LEDs also use phosphors -- in that way an LED is like a miniature fluorescent tube. Just like fluorescents, LEDs (at least those used for illumination) have an undesirable emission spectrum that's converted to "white" with a phosphor coated enclosure. (LEDs generally have a very narrow spectrum, and the GaN system used for lighting can produce blue and shorter wavelengths, depending on doping.)




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