2. COLOURCOLOUR Dr D Adriaens

3. What do we (not) see? Which / how many colours do we see?...many. A computer nowadays ‘sees’ over 16 million colours. The exact number? 16,777,216 (for 24-bits images); up to 281,474,976,710,656 (for 48-bits images). A human eye can see about 10,000,000 different colours (of course, when you’re not colour blind...)...and which / how many don’t we see? Let’s find out!!! Red, Orange, Yellow, Green, Blue, Violet,..., Jade, White, Black, Brown, Pink, Alizarin, Lavender, Amber, Maroon, Aquamarine, Beige, Turquoise,...

4. Metals: two (simultaneous) experiments... Iron (Fe) can be different colours: Silvery grey: iron metal (Fe 0 ) Green-yellow: iron oxalate (Fe 2+ ) Brown-red: blood cells, rust (Fe 3+ ) Blue: iron oxide (Fe 2+ and Fe 3+ ) Can we change the colour in a simple experiment?

5. Metals: two (simultaneous) experiments... Copper (Cu) can be different colours: Bronze: copper metal Black: copper oxide Red: copper oxide (again) Green: copper carbonate Blue: copper sulphate Can we change the colour in a simple experiment?

6. Metals: two (simultaneous) experiments... COPPER Bronze Black Red Green Blue IRON Silvery grey Green-yellow Brown-red Blue

7. Iron Oxalate xxxxxxxxx  www.acdlabs.com: Chemsketch Fe(COO) 2 2 CO 2 Fe

8. Copper Oxide www.acdlabs.com: Chemsketch CuO or Cu 2 OCuSO 4 H 2 +... 

9. Copper Carbonate www.acdlabs.com: Chemsketch Imagine CuCO 3 as CuO and CO 2...

10. COLOURS Red-Green Blue-Yellow Black-White Red: 700-635 Orange: 635-590 Yellow: 590-560 Green: 560-490 Blue: 490-450 Violet: 450-400

11. The webcam: an experiment... A webcam changes colours......into an electrical signal. Focusing lens – focuses the light to a smaller beam Filter – removes unwanted light CCD – captures light and changes it into electricity USB cable – to computer

12. The webcam: an experiment... The computer screen or the projector......changes this back into colour. What if something goes wrong?? A webcam changes colours......into an electrical signal.

13. The webcam: an experiment... Focusing lens – focuses the light to a smaller beam Filter – removes unwanted light CCD – captures light and changes it into electricity USB cable – to computer Filter – removes unwanted light The filter doesn’t work properly... 

14. COLOURS Red: 700-635 Orange: 635-590 Yellow: 590-560 Green: 560-490 Blue: 490-450 Violet: 450-400 Infrared: > 700 Ultraviolet: < 400

15. Now... How can we use it?