Week 8 Physics of Vision Flashcards
what does an optical system do
create an image from an object
what 3 quantities must be known in order to calculate of the image from the object when mirrored
1 distance between object and the vertex of the mirror
2 image distance to mirror vertex
3 focal length
how do mirrors and lenses form images
mirrors use reflection
lenses use refraction
what is Fermat’s principle/principle of least time
the path taken between two points by a ray of light is the path that can be traversed in the least time
what is a compound eye
when a variable number of small eyes function as independent photoreceptive units combine to produce an image
what is accommodation in terms of vision
ability of the lens to change its focus from distant to near objects
what is myopia
light entering the eye focuses in front of the retina
what is hyper myopia
light entering the eye focuses behind the retina
what is astigmatism
when rays propagate in two perpendicular planes have different foci in an optical system
define the two types of astigmatism
type 1 occurs with a perfect symmetrical optical system
type 2 occurs with a non-symmetric optical system
what is depth of field
range of distance within that the image of the subject is acceptably sharp
what is shallow depth of field
images where only the main subject of interest is enhanced
what is extended depth of field
images where the far images is in sharp focus
explain briefly how pinhole cameras work
there is pinhole that limits the light entering the camera by forcing light to enter as a single path so that the image is inverted
