extra (video) uitleg

lichtstralen en -bronnen https://youtu.be/Z0vz_lOpZbI

schaduwen https://www.youtube.com/watch?v=7AdyijS4TJ0

licht en kleur https://www.youtube.com/watch?v=IbtET15Xe-I

spiegelen https://www.youtube.com/watch?v=8I0sdgARdWQ

uv- en ir-straling https://www.youtube.com/watch?v=DFxEgyI5D0E