Optics Final Exam Concepts

What are the 5 types of Monochromatic Aberrations we learned about?

i) Spherical Aberrations

ii) Coma

iii) Radial Astigmatism

iv) Curvature of field

v) Distortion

Which Monochromatic Aberrations occur with points ON axis?

i) Spherical Aberrations

Which Monochromatic Aberrations occur only with points OFF axis?

i) Coma

ii) Radial Astigmatism

Which aberrations can be minimized with a small diameter aperture stop?

i) Spherical Aberrations

ii) Coma

Which lens designs have the most Coma?

Meniscus Lenses

Which lens designs have the least Coma?

Plano and Biconvex

Which monochromatic aberration occurs from tilting the lens?

Radial Astigmatism

In radial astigmatism, which principal meridian experiences the greater increase in magnitude of refracting power? aka, which is greater, K_T or K_S?

Tangential, K_T>K_S

Which effective power, E_T or E_S, has the greater magnitude? at any angle other than 0.

Tangential, E_{T >} E_S

If the tangential is the horizontal meridian, which line image will form closer to the lens?

Vertical

If the horizontal line image forms closer to the lens, which meridian is the tangential?

Vertical

If an object is displaced vertically, which meridian is the tangential? Sagittal?

Tangential = Vertical

Sagittal = Horizontal

If an object is displaced horizontally, which meridian is tangential? sagittal?

Tangential = Horizontal

Sagittal = Vertical

Which tilt is a lens tilted vertically (tilted about the horizontal)? Pantoscopic or Faceform?

Pantoscopic

Which meridian is Tangential in a Pantoscopic tilt? Sagittal?

Vertical; Horizontal

Which tilt is a lens tilted horizontally (tilted about the vertical)? Pantoscopic or Faceform?

Faceform

Which meridian is Tangential in a Faceform tilt? Sagittal?

Horizontal; Vertical

What helps us determine the front surface power of a given lens power that will completely eliminate radial astigmatism?

Tcsherning Ellipse

What is the range of lens powers that we can completely eliminate radial astigmatism?

Which type of lens power can we not completely eliminate radial astigmatism using a spherical front surface? (high hyperope/ high myope)

-25D to +10D;

High Plus Powered Lenses ( > +10D); High Hyperope

Which aberration occurs due to a flat object and a curved screen (curved conjugate image)?

Curvature of field

What is the name of a curved set of image points conjugate to a given object distance?

Petzval Surface

Which are the two most important aberrations to control in lens design (aka - which aberrations have the largest effect on a viewer viewing through spectacle lenses)?

i) Curvature of field

ii) Radial Astigmatism

What happens to curvature of field when you eliminate radial astigmatism of a spec using Tscherning Ellipse?

Curvature of field will be worsened

Which is the best lens design type?

Meniscus Lenses (Convex front, concave back) that reduce both radial astigmatism and curvature of field but don’t completely eliminate either

What distortion is caused by a plus lens at near?

pincushion (magnification of periphery > center)

What distortion is caused by a minus lens at near?

barrel (magnification of periphery < center)

What distortion is caused by a plus lens at distance?

Barrel

In a diverging system, H2 is (in front of/ behind) the system

in front of

In a diverging system, H2 is (in front of/ behind) F2

behind

In a converging system, H2 is (in front of/ behind) the system

Behind

In a converging system, H2 is (in front of/ behind) of F2

Front

f₁ is the length from ___ to ___

H1 to F₁

f_f is the length from ____ to ____

the front of the system; F₁

a is the length from ___ to ____

the front of the system; H1

f₂ is the length from ___ to ___

H2 to F₂

f_b is the length from ____ to ____

the back of the system; F₂

b is the length from ___ to ____

the back of the system; H2

When the unit magnification of a multicomponent system is m = +1, what does this tell you?

Object is at H1 and Image will be at H2

When the lateral magnification of a multicomponent system is m= -1, what does this tell you?

u_H1 = 2f₁

v_H2 = 2f₂

In a multicomponent system, the object location is defined as the distance from ___ to ___

H1; object

In a multicomponent system, the image location is defined as the distance from ___ to ___

H2; image

If the object and image are located at the nodal points of a multicomponent system, what does this tell you about its lateral magnification?

m = n_o/n_i

What is significant with cardinal points?

When light is reversed through a system, the pair stays in the same place but exchanges roles

The principal planes of a spherical interface coincide at ____

the vertex

The nodal points of a spherical interface coincide at the ______

center of curvature

The principal planes and nodal points of a thin lens will coincide at ____

the vertex

For a biconvex thick lens, H1 and H2 are _____

inside the lens

For a plano-convex thick lens, H1 and H2 are ____

coincident with the front and inside the lens respectively

For a convex meniscus thick lens, H1 and H2 are _____

in front of the lens

For a concave meniscus lens, H1 and H2 are ____

behind the lens

a(n) ____ is any device that limits the amount of light passing through a system

aperture

From the point of view of the object, the device that does the best job at limiting the amount of light passing through the system is called the _______

aperture stop

What are 5 examples of apertures?

small opening, pinhole, diaphragm, lens, mirror

Which component plays the role of the aperture stop depends on _______

the location of the object

The image of the aperture stop formed by any lenses in front of it is the _____

entrance pupil

What are the steps to determine which component is the entrance pupil?

1) Find the image of each component with respect to the component in front of it

2) Determine which component subtends the smallest angle using tanθ = o/a (where o is the radius of the image of the component formed by the lens in front of it and a is the distance from the obj to the img of the component)

The ___ ___ is the image of the aperture stop formed by any lenses behind it

exit pupil

what is the relationship between the entrance and exit pupils?

both are images conjugate to the aperture stop of the system

a ray that just passes through the aperture stop, and therefore goes through the edge of the entrance pupil is the ______

marginal ray

The ray that is aimed at the center of the entrance pupil and therefore passes through the center of the aperture stop is the ___ ray

chief ray

It is the ___ ray that determines the size of a blurred image when the screen is closer than the point image location

chief

Of the eye system, the entrance pupil is ____

the image of the eye’s pupil as seen through the cornea

Of the eye system, the aperture stop is ____

the anatomical pupil

When you look at someone’s eye, you are seeing the ______

entrance pupil

lateral magnification is based on ____ while angular magnification is based on _______

object and image distance; angle the nodal ray makes with the optical axis

when an object is far its retinal image will be _____ (smaller than/ bigger than/ the same size as) the retinal image of an object that is closer

smaller than

For an object inside the eyes primary focal point, a plus lens in front of the eye will produce a (small/large) (real/virtual) image

large; virtual

For a collimating magnifier to work, the object will be placed at ____ and ___ (converging/diverging/ plane) waves will exit the lens

F₁; plane

For the collimating magnifier formula (M = |u_e|P), u_e is _____ and the units must be ___

the object distance for the unaided eye (for when the magnifier is not present); meters

Does M_coll depend on lens-eye separation?

no - rays are parallel between the eye and lens (no vergence change)

angular magnification M compares ____ ____ _____

retinal image sizes

Maximum M_coll is when d = ___, which would be the _____ ____

0; mythical maximum

Maximum accommodation with a magnifier occurs when the plus lens forms its image at ____

u_e/ viewers near point

The lens closer to the object is called the ____ ___ (___)

objective lens (P_o)

The lens closer to the object is called the ____ ___ (___)

eyepiece/ocular lens (P_e)

In a simple compound microscope, the ____ lens acts as a collimating magnifier

eyepiece

For a compound microscope to have the eyepiece lens acting as a collimating magnifier, the objective lens must place it image at _____

The primary focal point of the eyepiece lens (F1 of P_e)

The formula for magnification of a collimating magnifier is

M= m_o|u_e|P_e

where m_o is the lateral magnification of the objective lens

The optical tube length of a compound microscope is

x’ (the distance between f₂ of P_o and f₁ of P_e)

The 3 formulas to calculate the standard magnification of a compound microscope are

The retinal image of a compound microscope will be (smaller/larger), (upright/inverted) compared to the object

larger, inverted

A compound microscope is used to view (large/small), (distant/ nearby) objects

small, nearby

A telescope is used to view (large/small), (distant/ nearby) objects

large, distant

A telescope is an afocal system because

it does not change the vergence of light

The length of a telescope is found by ____

secondary focal length of objective lens + primary focal length of eyepiece lens

An afocal lens with two plus powered lenses is a _____ telescope

Keplerian

For a Keplerian telescope, the retinal image will be (upright/inverted) with respect to the unaided eye

inverted

For a telescope to work, ____ must be incident

plane waves

An afocal telescope with a minus powered ocular lens is a ____ telescope

Galilean

For a Galilean telescope, the retinal image will be (upright/inverted) with respect to the unaided eye

upright

M for a Keplerian telescope is always (pos/neg) and for a Galilean telescope is always (pos/neg)

negative; positive

To produce an erect image with an erecting lens without changing the angular magnification, the telescope length must be increased a distance ___

4f_er (4x the focal length of the erecting lens)

If light exiting a telescope is diverging ____

the eye wont be able to accommodate enough to clearly view it

If the exiting light from a telescope is converging ___

the eye will be fogged

the goal of a reading cap is to _______

neutralize a nearby objects vergence so that plane waves are incident on the telescope

The formula for standard magnification of a telemicroscope is

A highly detailed object has a (high/low) spatial frequency

high

A low detailed object has a (high/low) spatial frequency

low

Spatial frequency tells us ____ per ____

oscillations; unit space

The image quality transferred by an optical system is ____, which compares ____ and _______ ____ ____

modulation; minimum and maximum detectable luminance