Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Virtual Reality > Chapter 4 > Flashcards

Chapter 4 Flashcards

1
Q

three descciptions of light

A

photons waves rays

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

photons

A

tiny particles of energy moving through space at high speeds - helpful when consdiering amount of light received by snesor or receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

waves

A

ripples thorugh space, wavelength is the distance between peaks - helpful when consdiering spectrum of colosr

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

rays

A

traces motion of single hypothetical photon and perpendicular to wavefronts - helpful when explaining lenses and defining concept of visibility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

wave spreading

A

desnity (photons per second per area) same in all directions but decrease as light source becomes more distant as well as curvature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

parallel wavefronts

A

if waves were to propagat infinitely far away then they would completely flatten

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

at a finite distance from a point light source…

A

rays of light diverge, impossible to make them converge without help of lenses and mirror

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

three behaviors as light strikes surface of material

A

transmission, absorption, reflection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

transmission

A

energy travel through material and exit other sit (glass) light rays are slowed and bend/ if translucent that is not tranpasrent, rays scatter into various directions before exiting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

absorption

A

energy is absorbed by the material as lightbecome trapped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

reflection

A

light deflected from surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

specular reflection

A

exit anygle is equal to entry engle on perfectly smooth surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

diffuse reflection

A

reflected rays are scattered in arbitrary directions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

ways energy is divided between cases

A

angle of approach, wavelength and differences between two adjacent materials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

coherent versus jumbled light

A

light sources do not emit coherent light (wavefronts perfectly aligned in time and space with exception of laser) / light bulbs and sun emit jumble that have various wavelengths and no peaks aligned

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

spectral color

A

perceive with coherent light source fixed at one wavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

700 - 100 nm

A

infrared no visible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

100 - 400 nm

A

ultraviolet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

perception of color

A

observe light relfected from ojbject around us / each surface has own distribution of wavelengths it reflects and fraction of light energy reflected back depend on ewavelength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

to perceive red as an object sruface what needs to happen

A

red wavelengths must be included in light source and surface must strongly relfect red wavelengths

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

frequency

A

number of times per second wave peaks pass through fixed location

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

snells law

A

how much rays of light bend when entering or extigin a transparent material
n1 sintheta1 = n2 sintheta 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

refractive index

A

n = c/s where is is speed of light in medium, n is how long it takes to traverse medium through vacuum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

prism

A

larger refractive index would cause greater bending inside

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

focal point

A

parallel horizontal rays of light converge to a point on the other side of the lens - convergence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

focal depth or length

A

distance from lens center

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

1/s1 + 1/s2 = 1/f

A

focal length is f, light source placed at distance s1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

if light source is too close to the lens

A

outgoing rays might be diverging so much that lens cannot force them to convergeand real image not formed

29
Q

magnification and vr

A

virtual image appears when looking into lens –several lenses placed in succession

30
Q

concave

A

parallel rays forced to diverge rather than converge

31
Q

diopter

A

D = 1/f , larger the D greater the converging power smaller the greater divergence

32
Q

aberrations

A

imperfections that dgrade images formed by lenses

33
Q

chromatic aberration

A

separates focuse image based on color

34
Q

how to reduce chromatic abertation

A

combine conves and concave lenses of different materials so they converge

35
Q

spherical aberration

A

caused by rays further away from lens center being refractoed more than rays near the center

36
Q

monochromatic aberration

A

independent of light wavelength - spherical aberration / incoming parallel rays focused at varying dpeths not concentrated at single point

37
Q

petzvel surface

A

image might focus on to curved surface the petzvel rather than image plane with spherical aberration

38
Q

aspehric lens

A

non spherical surfaces to eliminate spherical aberration

39
Q

optical distortions

A

distorted at the perhipheral - stretch or compress image

40
Q

two types of optical disotritons

A

barrel distorition and pincushion distortion

41
Q

fish eyed lens

A

vide field of view where distoriton is strongerand is a type of barrel distortion

42
Q

astigmatism

A

lens aberration that occurs for incoming rays not perpedicualr to the lens/ cornea has excessively elliptical shape rather than symmetruy

43
Q

coma

A

aberration where image magnification vaires dramatically as the rays are far from perpedicaulr to the lens

44
Q

lens flare

A

aberration where rays from birght light scatter through lens and show circular patters

45
Q

retina as related to focal plane

A

replaced by this spherically curved surface

46
Q

cornea and lens

A

two convex lenses

47
Q

accommodation

A

lens changes diopter to accommodate closer distance

48
Q

presbyiopia

A

as you age little or no accommodation ability remains - 50 yrs

49
Q

hyperopia or farsightness

A

opitcal system doesnt have enoguth optical power to converge parallel rays to retina

50
Q

fixing hyperopia

A

place convex lens with poistive diopter in fron of the eye

51
Q

myopia or near sighteness

A

when eyes have too much optical power

52
Q

how to fix myopia

A

concave lens with negative diopter is placed in front of eye to reduce optical power

53
Q

correct astigmatsm

A

non simple lenses

54
Q

vr headset screen and lenses

A

place it 10cm away and can focus , optical power increase dby convex lens - place at distance of ofcal length (x2 = -f meaning s1 = infinity resulting in screening apearing as enromous virtual image ininitye far away

55
Q

focusing knob

A

varies distance between lens and screen - adjusts opitcal power so rays between lens and cornea arent parallel and can be made to converge or diverge for hyperopia or myopia/ but if each eye needs different diopter than need knob for each eye and cant correct for astigmaism

56
Q

interpupillary distance

A

distance between human eye centers - 55-75mm

57
Q

camera obscura

A

allows light to pass through pinholle onto surface containing real image

58
Q

two technologies for electronically capturing image using a sensory with digital camers

A

charge coupled device array and cmos active pixel image sensor

59
Q

how do these digital technnologies work

A

record amount of light hitting each pixel location along image which directly procues a capture image

60
Q

what is the image in when cpatured on digital image

A

2d array of pixels, each having red green and blue 0-255

61
Q

higher resolution camera

A

less photons per pixels because pixels are smaller

62
Q

how to control amount of photons

A

shutter

63
Q

shutter

A

blocks light, lopens for fixed interval of time and closes

64
Q

low shutter speed

A

long interval, more light collected but moving objects might seem blurry and sensing elements could be saturated wtih too much lights

65
Q

how cmos sensors work

A

sned image info sequentially line by line so coupled with rolling shutter

66
Q

rolling shutter

A

sllows light to enter for each line just before info is snet and can get odd artifacts

67
Q

how ccd snesors work

A

grab and send entire image at once resuling in global shutter

68
Q

aperture lens

A

convex so multiple rays converge to same point on image plane genertating more photons per sensing elememnt / but focuses on objects on single dept while blurring others

Virtual Reality (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions