# Shared Flashcard Set

## Details

Optics
Geo Optics pgs 21-37
23
Physics
Professional
01/31/2012

Term
 Real objects have what kind of vergence?Virtual objects?
Definition
 Real objects: Divergence/ negative vergenceVirtual objects: Convergence/ positive vergence.
Term
 If light exits with positive or convergence will it form a real or virtual image?
Definition
 Real image
Term
 What is an umbra? What is a penumbra?
Definition
Term
 What is the power of a planoconvex thin lens in air with n'=1.56, whose curved surface has a radius of curvature of 6cm?
Definition
 9.33D
Term
 Define the secondary Focal point.Where is it located for + lenses? - lenses?
Definition
 location of the image point when light from infinity strikes the lens.+ --> to the right, real image- --> to the left, virtual image
Term
 Define primary focal point.
Definition
 the location of the object point from which light can leave as plane waves. @ infinity.
Term
 Where is the nodal point on a SSRI?
Definition
 Center of curvature --> the point through which light passes undeviated.
Term
 What is the lateral mag for an object height of 3cm and an image height of 6cm?
Definition
 2x
Term
 You look under water (n=1.50) and see a dinosaur 5 m below. What is its apparent depth?
Definition
 Apparent depth = d/n = 3.33 m Things look closer than they actually are in water!
Term
 When going to a higher n where does the angle of refraction bend?When going to a lower?
Definition
 Higher --> bends towards normalLower --> away from normal
Term
 What property of the cornea does Gonio overcome? What is this principle?
Definition
 Total internal reflection - when going to a lower refractive index there will be a critical angle such that angle angle will be totally reflected internally. Any light incident at an angle greater than this critical angle will also be reflected internally.
Term
 In our handy dandy step along equation, the sign is positive or negative when going from the corneal to spectacle plane?
Definition
 Positive: cornea - specNegative: spec - cornea
Term
 What does the image of the human eye look like?
Definition
 Minified and inverted
Term
 As you increase n, what happens to vergence? Increase or decrease?
Definition
 Increasing n increased the change in vergence
Term
 In what case does equivalent power become just the sum of the surface powers?
Definition
 When the thickness is 0.
Term
 What are prescriptions specified using?
Definition
 Back vertex power. Also how a lens is red in lensometry
Term
 What is the back vertex power?
Definition
 vergence of light exiting the optical system given that plane waves entered
Term
 In what case do the principle points and nodal points coincide
Definition
 If the lens is surrounded on both sides by the same material. n1=n3, f = -f'
Term
 What does the aperture stop limit? What is the aperture stop in the eye?
Definition
 limits Amount of light that can enter the system. The pupil is the aperture stop in the eye
Term
 What does the field stop limit? What do the aperture stop and field stop together limit?
Definition
 Field stop limits the size of the object that can be images. The aperture stop and the field stop limit the field of view
Term
 What is the entrance pupil? What is the entrance pupil in the eye?
Definition
 The entrance pupil is the image of the aperture stop formed by all the lenses that lie in front of it. In the eye: View of the iris through the cornea
Term
 If you increase the F#/focal ratio of a camera, will more or less light enter the system
Definition
 Decreases. f/ = f/D (D is the diameter of the entrance pupil)
Term
 What is the entrance port?
Definition
 The image of the field stop formed by lenses in front of it
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