Thursday 13 June 2013

How light works

I've just started the higher photography course at school and I thought I'd share some of my recently gained useful photography know how with you all...

Light waves come in different frequencies that relate to the energy of the wave. As humans, we can only see the visible spectrum which sits in middle part of the frequency table; so we can't see things like gamma rays because they're too high a frequency and we can't see microwaves because they're too low a frequency.

Focusing on the visible spectrum what happens to light when it hits something depends on three things...the frequency of the wave, the strength with which atoms in the material hold on to their electrons and the energy of the light wave. This can create a few different effects:



Reflection:

Like in mirrors. Light rays don't penetrate the object deeply and electrons holding the energy pass it straight back out at the same frequency. 

Transmission:

Objects like glass seem transparent because the light frequency is too high to make the electrons vibrate so that the light rays aren't captured and pass straight through the material.










Refraction: 

Light rays are slowed down and bent, creating a glittery effect like water on a brilliantly sunny day or diamonds.




Absorption:

Electrons are absorbed so rays don't bounce back and materials are opaque like wood.



Scattering:

Light rays are thrown in loads of different directions by a rough surface like that of paper.






I hope you guys have found this if not helpful, a little bit interesting and by the way, the images on this post aren't my own!

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