# Shared Flashcard Set

## Details

ILC
ILC Sept 07
67
Fine Art
09/10/2007

Term
 atom
Definition
 the smallest particle of a substance
Term
 electron
Definition
 negatively charged particle
Term
 proton
Definition
 positively charged particle
Term
 stable atom
Definition
 equal # of protons and electrons
Term
 law of charges
Definition
 like charges repel, unlike charges attract
Term
 electron shell
Definition
 an orbit that can hold a set number of electrons
Term
 current
Definition
 flow of electrons from one point to another
Term
 amp
Definition
 measurement of current (electron flow)
Term
 potential
Definition
 difference in electrical charge between two bodies
Term
 volt
Definition
 measurement of potential (difference in charge)
Term
 resistance
Definition
 opposition offered by a substance to passage of electric current
Term
 ohm
Definition
 measurement of resistance
Term
 difference between parallel and series circuit
Definition
 if one part of series fails, all paths fail; if one part of parallel fails, the rest continues working
Term
Definition
 a device that converts electricity into light, heat, or mechanical energy
Term
 wires in typical AC circuit; what they're used for
Definition
 ground to earth, neutral return path, hot transmits power
Term
 three types of connectors used on lighting fixtures
Definition
 Edison, Twist Lock, Stage Pin
Term
 typical Edison connector wiring
Definition
 black to gold (hot), white to silver (neutral), green to green (ground)
Term
 what Ohm's Law measures
Definition
 resistance in a circuit
Term
 formula for power consumption
Definition
 W=VxA
Term
 what light does
Definition
 makes vision possible
Term
 4 properties of light that influence the way we perceive an object
Definition
 intensity, color, sharpness, angle
Term
 why can light be considered a particle?
Definition
 particles travel in straight lines and can travel through a vacuum
Term
 why can light be considered a wave?
Definition
 has properties of waves
Term
 properties of waves
Definition
 diffraction, reflection, refraction
Term
 diffraction
Definition
 waves that pass around/through an object will fill in behind object
Term
 refraction
Definition
 waves change direction as they pass from one medium to another
Term
 visible spectrum
Definition
 wavelengths of light we can see - 400 to 700 nanometers
Term
 what a reflector does
Definition
 control light: collect light, redirect light, create point source
Term
 how a reflector works
Definition
 laws of specular reflection: angle of incidence = angle of reflection
Term
 point of incidence
Definition
 where light strikes the surface of reflector
Term
 angle of incidence
Definition
 angle at which light strikes surface
Term
 angle of reflection
Definition
 angle at which light is reflected off surface
Term
 3 examples of specular reflectors
Definition
 mirrors, polished metals, calm water
Term
 what a diffuse reflector does
Definition
 maximum dispersion of rays
Term
 example of a near zero reflector
Definition
 black velour
Term
 3 types of reflectors commonly used in lighting fixtures
Definition
 ellipsoidal, spherical, parabolic, asymmetrical
Term
 what does an ellipsoidal reflector do?
Definition
 collect large portion of light, focus to secondary point. creates intense cone of light
Term
 what does a spherical reflector do?
Definition
 smaller cone of light equal to lens
Term
 what does a parabolic reflector do?
Definition
 rays reflected parallel. creates oval beam of light. concentrate center, diffuse edges.
Term
 what does a lens do?
Definition
 bend light, focus light
Term
 refraction
Definition
 bending light rays by passing through mediums of different optical densities
Term
 speed of light
Definition
 186,200 miles/second in a vacuum
Term
 optical density
Definition
 speed of light in a medium
Term
 three conditions that influence the bending of light through a lens
Definition
 1) ratio between incidences of refraction 2) difference in angles of normal 3) wavelength of light
Term
 focal length of a lens
Definition
 distance from optical center to principal foci
Term
 types of lenses used in lighting fixtures
Definition
 plano-convex, fresnel, par
Term
 what type of lens is a plano convex lens?
Definition
 positive spherical
Term
 conventional fixtures commonly used in theater
Definition
 ERS, Leko, Fresnels, Par Cans, Cyc lights, strip lights, scoops, follow spots
Term
 what does ERS stand for?
Definition
 Ellipsoidal Reflector Spotlight
Term
 type of lens used in ERS
Definition
 plano convex lens
Term
 part of optic train where gobos and shutters are placed
Definition
 gate
Term
 what ERS fixtures are commonly used for
Definition
 front lights, key lights, specials, pattern projectors, follow spots, wash lights, effect projectors
Term
 what Fresnel lens was originally developed for
Definition
 lighthouses
Term
 what is special about the Fresnel lens?
Definition
 step lens - retains focal properties of plano convex
Term
 type of light produced by Fresnel lens
Definition
 soft circle
Term
 type of reflector used in Fresnel fixture
Definition
Term
 common uses for Fresnel
Definition
 wash lights, soft spots, large pools, scenery lights, down lights
Term
 type of lamp used in Par Can
Definition
 sealed beam lamp
Term
 type of reflector used in Par lamp
Definition
 Parabolic Aluminized Reflector
Term
 how to focus a Par Can
Definition
 twist ceramic on back opening - change angle of oval
Term
 lamp designations used in standard Par Cans
Definition
 NSP, VNSP, MFL, WFL
Term
 what Par Cans are typically used for
Definition
 color wash, down light, back light, air light, side light
Term
 type of light used to light a back drop
Definition
 strip lights
Term
 what a strip light is used for
Definition
Term
 what a scoop is used for
Definition
 general wash, good work-lights
Term
 what is used to focus a follow-spot
Definition
 a trombone
Term
 where color is held in a follow spot
Definition
 boomerang
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