Qualities in Lighting Stage lighting

1 qualities in lighting

1.1 intensity
1.2 colour
1.3 direction
1.4 focus, position, , hanging

qualities in lighting
intensity

an example of rig including moving head, generic , led fixtures @ tuesday club

intensity measured in lux, lumens , foot-candles. intensity of luminaire (lighting instrument or fixture) depends on number of factors including lamp power, design of instrument (and efficiency), optical obstructions such colour gels or mechanical filters, distance area lit , beam or field angle of fixture, colour , material lit, , relative contrasts other regions of illumination.

colour

colour temperature measured in kelvins. light s apparent colour determined lamp colour, colour of gels in optical path, power level, , colour of material lights.

a tungsten lamp s colour typically controlled inserting 1 or more gels (filters) optical path. in simplest case, single gel inserted optical path produce light of same color. example, blue gel used create blue light. custom colours obtained means of subtractive cmy colour mixing, inserting combinations of cyan, magenta , yellow filters optical path of lighting fixture. inserted filters may have varying densities, correspondingly varied percentages of transmission, subtractively mix colours. creates custom colours in manner similar ink jet printers, mix varied densities of cyan, magenta , yellow inks. manufacturers include additional green or amber ( cto colour correction) filter extend range (gamut) of subtractive colour mixing systems,

lamp power influences colour in tungsten lamps. lamp power decreased, tungsten filament in bulb tend produce increasing percentages of orange light, compared white light emitted @ full power. known amber drift or amber shift. 1000-watt instrument @ 50 percent power emit higher percentage of orange light 500-watt instrument operating @ full power.

led fixtures create colour through additive colour mixing red, green, blue, , in cases amber, leds @ different intensities. type of color mixing used borderlights , cyclorama lights.

direction

direction refers shape, quality , evenness of lamp s output. pattern of light instrument makes largely determined 3 factors. first specifics of lamp, reflector , lens assembly. different mounting positions lamp (axial, base up, base down), different sizes , shapes of reflector , nature of lens (or lenses) being used can affect pattern of light. secondly, specifics of how lamp focused affect pattern. in ellipsoidal reflector spotlights (ers) or profile spotlights, there 2 beams of light emitted lamp. when cones of both intersect @ throw distance (the distance stage), lamp has sharply defined hard edge. when 2 cones not intersect @ distance, edge fuzzy , soft . depending on beam (direct or reflected) outside other, pattern may thin , soft or fat , soft . lastly, gobo or break pattern may applied erss , similar instruments. typically thin sheet of metal shape cut it. inserted instrument near aperture. gobos, or templates, come in many shapes, include leaves, waves, stars , similar patterns.

focus, position, , hanging

many stage lights hang on batten focused in several directions

the focus instrument pointed. final focus should place hot spot of beam @ actor s head level when standing @ centre of instrument s assigned focus area on stage. position refers location of instrument in theater s fly system or on permanent pipes in front-of-house locations. hanging act of placing instrument in assigned position.

moving lights hanging on truss, ready rigging , chain motors.

in addition these, modern instruments automated, referring motorized movement of either entire fixture body or movement of mirror placed in front of outermost lens. these fixtures , more traditional follow spots add direction , motion relevant characteristics of light. automated fixtures fall either moving head or moving mirror/scanner category. scanners have body contains lamp, circuit boards, transformer, , effects (color, gobo, iris etc.) devices. mirror panned , tilted in desired position pan , tilt motors, thereby causing light beam move. moving head fixtures have effects , lamp assembly inside head transformers , other electronics in base or external ballast. there advantages , disadvantages both. scanners typically faster , less costly moving head units have narrower range of movement. moving head fixtures have larger range of movement more natural inertial movement typically more expensive.

the above characteristics not static, , variation in these characteristics used in achieving goals of lighting.

stanley mccandless perhaps first define controllable qualities of light used in theater. in method lighting stage, mccandless discusses color, distribution, intensity , movement qualities can manipulated lighting designer achieve desired visual, emotional , thematic on stage. mccandless method, outlined in book, embraced today. method involves lighting object on stage 3 angles—2 lights @ 45 degrees left , right, , 1 @ 90 degrees (perpendicular front of object).

an alternative formulation jody briggs, calls them variable of light: angle, color, intensity, distance, texture, edge-quality, size, , shape.