The Difference Between ‘Violet’ and ‘Purple’ (2015)

Re:The Difference Between ‘Violet’ and ‘Purple’ (2015) by blincoln on Tuesday April 02, 2019 @12:49PM (#19556152)

This is a bit of a nitpick, but most people (especially children) can see at least a bit into UV. With my contacts in, I can see down to about 400-410nm. With them out, I can see to about 390nm, because the plastic in the contacts blocks shorter wavelengths. I tested this using a spectrophotometer.

People who have had cornea-replacement surgery and opted for the UV-transparent corneas can see further into the UV.[1] A child (with young corneas that haven't yellowed at all) almost certainly can too.

[1] e.g. http://www.komar.org/faq/colorado-cataract-surgery-crystalen...

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Re:The Difference Between ‘Violet’ and ‘Purple’ (2015) by rmilk on Tuesday April 02, 2019 @04:41PM (#19558363)

Slighly off topic, but UV visibility is important in other species. See this link for photos of flowers showing how they appear to bees or birds.

The CIE charts don’t really consider how to interpret or recolor data outside the color space, for example the UV reflection from flowers or astronomy photos in the UV/X-ray spectrum.

http://www.naturfotograf.com/UV_flowers_list.html#top/

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Re:The Difference Between ‘Violet’ and ‘Purple’ (2015) by jacobolus on Tuesday April 02, 2019 @02:43PM (#19557286)

Fair enough. I guess that part is down to definition of “ultraviolet”. The wavelengths called “UV-A” are slightly visible to some human observers.

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