Reflection

• specular reflection is when the light is reflected off a smooth surface and is reflected back in the same direction, it creates a clear image
• diffuse/scattered reflection is when 2 waves meet and the waves are scattered in different directions, boundary is bumpy
• total internal reflection can only happen when the light is travelling from a denser medium to a rarer (less dense) medium
• whether total internal reflection occurs is if the angle of incidence is greater than the critical angle
• if the angle of incidence is less than the critical angle then most of the light passes out. but some is internally reflected
• as the angle of incidence increases, more light gets internally reflected and less light is refracted out.

  if its bigger than the critical angle no light is reflected and all the light is internally reflected
• refractive index = 1/SinC
• the critical angle is the angle of incidence in denser mediums when the angle of refraction is 90 degrees
• when light travels from a less dense medium to a more dense medium it bends towards the normal
• when light travels from a more dense medium to a less dense medium it bends away from the normal line
• the conditions of the critical angle are: 1. incident angle must be in denser medium 2. refracted angle in less dense medium = 90degrees
• Total internal reflection is when the angle of incidence is larger than the critical angle, so no light is refracted, reflected internally
• conditions of TIR: 1. light travels from denser to rarer ( less dense ) medium. 2. incident angle>critical angle