visiable light (seeing colour.) Flashcards
what is the law of reflection?
angle of reflection is equal to the angle of incidence.
how are non-luminous objects visiable?
light is scatterd off them into the eyes.
name and explain this diagram: prisim with a beam of light through it.
dispersion. light with different wavelengths are refracted by different amounts.
what two types of reflection are there?
specular and diffuse.
property and example of specular reflection.
smooth.
mirror.
property and example of diffuse reflection.
rough.
sheet of paper.
how do the rays in a specular reflection meet a surface?
from one direction and reflected in the same direction.
how do the rays in a diffuse reflection meet a surface?
when the light reflects off a rough surface although each ray obeys the law of reflection as the different parts of the rough surface point in different directions, so different rays coming from the same direction are reflected or scatterd in different directions.
how many types or receptors do human eyes have and what are they responsible for?
3.
seeing colour.
what do the peak sensitivites in each receptor corrospond to?
wavelengths in the red, green and blue parts of the visiable spectrum.
how are colours other than red, green and blue seen?
combination of responses from two or more types of receptors.
what are objects that are opaque not do?
transmit any wavelengths of light.
how is the colour of an oppaque object determined?
by the wavelngth of the light that are reflected most strongly. all other wavelngths are absorbed.
what does a filter allow?
only a small range of wavelengths to pass through.
