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67 Cards in this Set
- Front
- Back
whats a collimator
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any optical element that produces parallel light leaving
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what is a visual angle
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the angle subtended by the OBJECT at the NODAL point of eye
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angular magnification=
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(visual angle through device)/(visual angle w/o device)
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optical tube length of a microscope is equal to
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the distance between the secondary focal point of the objective and the primary focal point of the eyepiece
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f-number on camera lens is related to the diameter of
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aperture stop
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spectral energy distribution of a black body is dependent upon the black body's...
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temperature
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what type of emission is used to produce light from a laser
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stimulated emission
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when the peak visual sensitivity is at 500nm, the eye is in...? 555nm??
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a. scotopic
b. photopic |
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Angular Magnification for:
Accomodation No Accomodation |
Accomodation: AM=(F/4)+1
No Accomodation: AM=(F/4) |
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Astronomical Telescopes use what type of lenses
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two POSITIVE lens
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describe astronomical telescope
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1. parellel rays from distance object
2. Obj. forms a real image in secondary focal plane of the obj. 3. real IMAGE acts as a real OBJ for eyepiece 4. primary focal point of the eyepiece coincides with the secondary focal point of the obj. 5. rays leave the eyepiece parallel |
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distance between two lens in astronomical? galilean?
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astronomical: d=f'o+f'e
galilean: same addition of the two SECONDARY focal length |
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galilean telescope properties
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POS. obj. lens
NEG. eyepiece lens MAGNIFIED ERECT IMAGE |
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astronomical or galilean?
Larger field of view |
astronomical
galilean: smaller field of view |
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astronomical or galilean?
erect |
galilean
astronomical: is inverted |
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astronomical or galilean?
longer for same magnification |
astronomical
galilean: shorter for same magnification |
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in galilean telescope...what is the eye relief
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distance from eyepiece to exit pupil
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what is a reading cap
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a reading cap is added to a telescope so near objects can be viewed
acts as a collimator near object at focal pt. of reading cap |
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what is an aperture stop and what are the factors that determine it
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the element of an optical system that determines the brightness of an ON-AXIS image point
1. diameter of element 2. location of element in sys. 3. object location |
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entrance pupil
what is there is no lense in front of the aperture stop |
iamge of the aperture stop formed by the lensed in FRONT of the aperture stop
the aperture stop is the entrance pupil |
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exit pupil
what if there is not lens behind the aperture stop |
image of the aperture stop formed by the lenses BEHIND the aperture stop
the aperture stop is the exil pupil |
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chief ray
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ray from an object point that passes through the axial point, in the plane of the entrance pupil
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field stop
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optical element whose aperture limits the size or angular width of the object that can be imaged by the system
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vignette
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chief ray get through the system but a marginal ray cannot
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entrance window
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image of the field stop formed by all the optical elements PRECEDING it
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exit window
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image of the field stop formed by all optical elements FOLLOWING it
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can an element in an optical system be BOTH the AS and FS
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FUCK NO
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f-number
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ratio of focal length of the lens to the aperture stop's diameter
f-number= focal length/diameter of AS |
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what is depth of focus
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total axial range over which the image plane can be moved without noticeable deterioration in the image definition
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what two factors determine depth of focus
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1. size of aperture stop
2. max size of undetectable blur circle on the image plane |
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explain graybody
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radiation from real rediator is always less than that of the blackbody and is accounted by "emissivity"
emissivity: true blackbody=1 graybody<1 |
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graybody and blackbody in terms of wavelength
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graybody varies by wavelength
blackbody NOT varied by wavelength |
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where does an atom fall in fluorescence? phosphorescence?
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fluorescence: INTERIM level
phosphorescence: METASTABLE level |
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THREE laser components
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1. population inversion
2. stimulated emission 3. light amplification |
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radiometry vs. photometry
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radiometry: interaction with matter
photometry: detection by the human eye |
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radiant flux
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POWER
time rate of flow of radiant energy |
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Radiant exitance
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radiant power emitted per unit of area
COMING OFF SURFACE |
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irradiance
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radiant power emitted per unit of area
GOING ON SURFACE |
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radiant intensity
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radiant flux in a unit per solid angle
incident on, passing through, or emerging from point source |
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radiance
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radiant intensity per projected area
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how many watts is 1 talbot
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1 talbot=683 watts
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Luminous Power
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photometric equivalent to radiant flux
measured in lumens |
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Luminance exitance
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1. photometric equivalent to radiant exitance
2. luminance power COMING OFF an area measured in Lumen/m^2 (lux) |
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Illuminance
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1. photometric equivalent to irradiance
2. luminance power GOING ON an area measured in Lumen/m^2 (lux) |
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Luminance Intensity
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photometric equivalent to radiant intensity
measured in lumens/steradians (candela) |
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Luminance
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photometric equivalent to radiance
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Lambertian surface properties
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ideal surface for which the radiation coming from that surface is distributed angularly by: I(theta)=(Io)(cos(theta))
extended surface is Lambertian: L=constant radiance and luminance of Lambertian surface is the same in all directions |
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transmittance
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the ratio of the amount of light transmitted to the amount of light incident
measured at the same wavelength |
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absorbance
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optical density
the log base 10 of the inverse of the transmittance |
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how do you take into consideration multiple transmittance? absorbance?
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transmittance: multiplicative
absorbance: additive |
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general absorbance v.s. selective absorbance
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general: same over near the entire spectrum
selective: certain wavelength (i.e. blue glass ONLY lets green, blue and violet THROUGH) |
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transmittance
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the ratio of the amount of light transmitted to the amount of light incident
measured at the same wavelength |
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absorbance
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optical density
the log base 10 of the inverse of the transmittance |
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how do you take into consideration multiple transmittance? absorbance?
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transmittance: multiplicative
absorbance: additive |
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general absorbance v.s. selective absorbance
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general: same over near the entire spectrum
selective: certain wavelength (i.e. blue glass ONLY lets green, blue and violet THROUGH) |
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An afocal telescope is used by a MYOPE. In order to obtain a clear image of an infinite object, the adjustment made would be to
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Move the eyepiece CLOSER to the objective
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An afocal telescope is used by a HYPEROPE. In order to obtain a clear image of an infinite object, the adjustment made would be to
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Move the eyepiece AWAY from the objective
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For a simple magnifier, the object position, which will yield parallel rays after refraction is
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Coincident with the primary focal point of the magnifier
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The aperture stop of an astronomical telescope is the
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objective
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the spectral energy distribution of a black body is dependent upon the black body’s
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temperature
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Red glass filter can
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transmit red light
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The optical density of a piece of material is equal to
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The absorbance of the material, A
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the centers of the AS and the EnP(or ExP) is considered to be...with one another
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CONJUGATE
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what happens to the freq. of a black body when the temperature increases
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freq increases with temperature
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in order to use a laser for surgery the tissue of regard must...the wavelength
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ABSORB
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object field of view
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formed by the angle subtended by the entrance window and the center of the entrance pupil
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image filed of view
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formed by the angle subtended by the exit window and the center of exit pupil
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