Sponsored by Dashlane. Get Dashlane on free on your fist device at https://dashlane.com/steve. And 10% off premium with promo code: steve There's a mismatch between the sensitivity of colour pixels in a digital camera sensor and the sensitivity of colour sensing cells in the human eye. We don't normally notice until we try to take a picture of the whole visible spectrum (like in a rainbow!). For example if you take a picture of a rainbow with a goPro Hero 7 violet disappears! I also talk about how computer screens can show violet even though the pixels only go as far as blue. Here's my video about how cones cells work: https://www.youtube.com/watch?v=dvovtbLGaUw You can buy my books here: https://stevemould.com/books You can support me on Patreon here: https://www.patreon.com/stevemould just like these amazing people: Glenn Watson Peter Turner Joël van der Loo Matthew Cocke Mark Brouwer Deneb Twitter: http://twitter.com/moulds Instagram: https://www.instagram.com/stevemouldscience/ Facebook: https://www.facebook.com/stevemouldscience/ Buy nerdy maths things: http://mathsgear.co.uk/