Microscope/telescope

Question 1

microscope

Answer 1

• 2 lens system

- real converging, inverted, magnified

Question 2

total magnification of microscope

Answer 2

Mtot=M1 x M2 (essentially squared)

Question 3

image and rays at the eye piece

Answer 3

-the parallel rays NEVER converge, the image is at optical infinity, can not ray trace the image, virtual optical infinity

Question 4

final image through microscope

Answer 4

has magnification substantially more than 1

Question 5

magnification of eye piece!!

Answer 5

Mep= 25cm/fe+1

eye piece is essentially a magnifying lens

Question 6

microscope magnification

Answer 6

M=M(objective) x M(eye piece) = (- L/f0) x (25cm/fe)

Question 7

resolution limit

Answer 7

• how sharp/clear an image is
• tell the difference between two points
• minimum angle of resolution (MAR), the smaller the better!
• expressed in angles or length

Question 8

resolving power (ability)

Answer 8

• 1/resolution
• reciprocal of the resolution limit
• LARGER is better
• expressed in inverse angles, or inverse length

Question 9

what does resolution depend on?

Answer 9

wavelength

Question 10

what can the human eye resolve

Answer 10

around 1 arcmin

Question 11

useful magnification

Answer 11

• eye can only pick up so much
• no sense in over magnifying if eye can’t pick it up
• about 0.25m (near point)

Question 12

what is a telescope?

Answer 12

two lens system

Question 13

What is the image of the first lens in the telescope?

Answer 13

the object for the second lens.

Question 14

What is the first lens in a telescope?

Answer 14

objective lens

Question 15

what is the second lens in a telescope?

Answer 15

the eye piece

Question 16

What is the beam vergence of incoming rays in telescope?

Answer 16

collimated, 0 beam vergence

Question 17

what is the beam vergence of outgoing rays in a telescope?

Answer 17

collimated, 0 vergence

Question 18

Where is the object located in telescope?

Answer 18

optical infinity

Question 19

What is the difference between the two collimated incoming/outgoing rays?

Answer 19

the incoming rays have a much larger diameter than the outgoing rays

Question 20

What does a telescope ultimately do?

Answer 20

condense large things into smaller rays of light

Question 21

What is the total optical power of a telescope?

Answer 21

0
-0 beam veregence coming in and going out
Po+Pe-(d/1)Po(Pe)=0

Question 22

where are the principal planes of a telescope?

Answer 22

at infinity

Question 23

magnification of telescope

Answer 23

-microscope and the telescope are based on magnification of a magnified image, and thus the total magnification is the product of the two individual magnifications, the primary, from the objective lens, and the secondary from the eye piece

Question 24

What kind of vergence does a microscope have?

Answer 24

strong vergence

Question 25

what kind of vergence does a telescope have?

Answer 25

no vergence

Question 26

What do you observe with a microscope?

Answer 26

a near object

Question 27

what do you observe with a telescope?

Answer 27

distant object

Question 28

lens separation in a microscope

Answer 28

larger than the sum of the focal distances

Question 29

lens separation in a telescope

Answer 29

equal to sum of the focal distances

Question 30

what are the properties of an image seen through a microscope?

Answer 30

-magnified, inverted, dimmer

Question 31

what are the properties of an image seen through a telescope?

Answer 31

- minified, inverted, brighter | - changes apparent angle in which we view the object

Question 32

is the telescope actually magnifying?

Answer 32

- contrary to a microscope, the telescope lateral magnification is smaller than 1: we may observe a real image of the sun projected o a screen with a telescope - the image's diamter is far smaller than that of the sun, and thus the lateral magnification is a very small number - this image, however is perhaps 20 to 50 times larger than what it would appear through the naked eye

Question 33

What sets the limit of resolution in any optical system?

Answer 33

-diffraction from circular aperature

Question 34

minimum angle of resolution

Answer 34

=(1.22 X wavelength)/(objective lens diameter)

Question 35

telescope resolution

Answer 35

- we unsuccessfully observe a double star with a telescope (no double star resolution) - to improve resolution, we decide to employ a chromatic filter - You want the angle of resolution to be at it's smallest, so put a blue filter on to make the angle smaller

Question 36

smaller angle of resolution...

Answer 36

larger objective lens diamter

Question 37

Why do some stars appear as 1, when there are acatually 2 or 3?

Answer 37

because the angle of resolution is so small you cannot differentiate

Question 38

What can the eye resolve?

Answer 38

about 1'

Question 39

what can a telescope resolve?

Answer 39

about 1"

Question 40

Kepler type telescope

Answer 40

- astronomical - length of telescope is the focal length - two plus lenses - virtual image at optical infinity - d=Fo+Fe

Question 41

Galilei type telescope

Answer 41

- terrestrial - low vision aids in optometry - erect image at optical infinity - d=Fo-Fe

Question 42

What lens has the biggest diameter in a kepler type telescope?

Answer 42

objective lens

Question 43

What lens has the biggest power in a kepler type telescope?

Answer 43

eye piece

Question 44

What is a problem with using a very large diameter lens?

Answer 44

weighgt, cost

Question 45

galilei type telescope and visual aid

Answer 45

- erect shorter image | - 2 lenses, not fused, there is air between them

Question 46

newtonian refractor

Answer 46

defflector on side

Question 47

catadioptric telescopes

Answer 47

combo of mirrors and optics

Question 48

What is chromatic abberation related to?

Answer 48

refraction

Question 49

how many surfaces in reflecting telescopes?

Answer 49

1

Question 50

Where is the support needed in a reflecting telescope for the lens?

Answer 50

in the back

Question 51

why do stars twinkle?

Answer 51

the atmosphere is a nonuniform lens scattering the layers

Question 52

a telescope can only be as good as...

Answer 52

the atmospheric conditions

Question 53

adaptive optics

Answer 53

-atmospheric turbulence can cause distorted wavefront