1. Lighting Instruments

2. Fresnel Oldest still existing lighting instrument used in theatre
August Fresnel: used light passing through a dense medium glass
When light is projected through glass, the beam is altered
Plano-convex lens: flat on one side and curved on the other
Most lenses “pebbled” with rough texture on back so light emitted is more diffuse (covers up irregularities in beam of light)
Use reflector shaped like a sphere to bounce light vaguely back in direction of lens
Both lamp and reflector are fastened to a “sled” that can move back and forth
The closer the sled is to the lens, the more spread out the beam pattern (FLOOD)
When sled is moved away from lens, beam output is sharpened (SPOT)
Light output is always somewhat diffuse with “hot” spot in center and lessening of intensity outward
Fresnel

3. Fresnel Accessories 6” and 8” : common sizes of Fresnels
Barn Door: limits the spread of the beam with adjustable flaps
Top Hat: circular piece that limits the spread of the beam
Gel: Color sheet placed in front of the light to alter color
Color Frame: holds the color gel in place
Fresnel is commonly replaced with source four Parnel
Barn Door Top Hat Color Frame
Fresnel Accessories

4. Ellipsoidal Reflector Spotlight – Source Four
Commonly used in theatre lighting due to their ability to shape the light in the beam produced
Uses two focal points to shoot light at specific angles
Uses plano-convex lens to further focus light
Uniform in intensity
Useful features: qualities of high intensity, a coherent beam, adjustable focus
Ellipsoidal Reflector Spotlight – Source Four

5. ERS – Source Four Features
Gate: area where shaping of beam occurs
Shutters: allow for masking of beam from each side
Gobos: templates of steel that create patterns
patterns must be inserted upside down and backwards to produce project properly
Gobo Holder: Metal frame that holds Gobo in place
ERS – Source Four Features

6. ERS – Source Four Angle Qualities
Light increases at a given angle; farther away light is from stage, more spread out the light will be
Ellipsoidals are measured according to two factors: diameter of lens and distance between focal points
Deciding instruments
Large diameter lenses enable a bigger fixture that can hold higher wattage lamp
Distance between focal points determines the amount of spread that occurs in beam angle
The farther apart the focal points, the narrower the angle
6X6 (50 degree) = wider beam (intended closer)
6X22 (19 degree) = narrower beam (intended further away)
ERS – Source Four Angle Qualities

7. Parabolic Aluminized Reflector – PAR
Essentially round car headlights with 110 volts
Simple, lightweight fixtures, inexpensive
Reflects straight outward whatever light rays strike it
Lens is meant to blur light beam into more homogenous pool
Beam is oval shaped and does not allow for changing from spot to flood
Variety of lamps offered for different angles
Possible to rotate the lamp within its housing to change orientation of oval beam from vertical to horizontal
Sizes: 64, 56, 38
Modern PAR’s have standard reflector and lamp/lens is changed to alter beam
“Bottle”: a ring used to rotate/change direction of oval
Parabolic Aluminized Reflector – PAR

8. Ellipsoidal Reflector Light (“Scoop”)
Primarily used to light drops and cycs
Lensless instrument with a wide, smooth wash of light
Equipped with a large color-frame holder
Common theater sizes: 14”, 16”, 18”
Ellipsoidal Reflector Light (“Scoop”)

9. Strip Lights or Cyc Lights
known also as border lights
have a number of lights strewn together by parallel circuit
typical unit has 2-4 lamps in each circuit depending on size and/or wattage
mini strips have large number of small lamps placed in groups of two
commonly used across a cyc
by using different colors in each circuit, colors on cyc can be mixed together
best to use one set from above and one from below to fill cyc
sizes: described by length – either 6’ or 8’ or single cell
Strip Lights or Cyc Lights

11. Dowser – varies intensity of light output and to black out spot so no light gets on stage
Iris – system of thin, curved metal plates in a moveable housing
-acts a lot like shutters in an ellipsoidal except creates round shape
-changing size of opening changes size of light
-far from stage = smaller iris/pool of light
-close to stage = larger iris/pool of light
-DO NOT use Iris to black out stage – extremely close to light source so has greater potential to overheat
Trombone – varies size of light
-handle on side of light can be pulled back and forth
-changes relationship between light source and lens mechanism
-used more often in arena shows when performers change depth quickly
Chopper – used to cut off top and bottom of light to gain a horizontal strip
Follow Spots

12. Boomerang – color changer
-normally six colors are available
-gels are loaded into round frames designed for light
-levers are outside of instrument to bring up each color
Diffusion Filter – causes light to change from sharp edge to soft edged beam
Targeting Device – helps focus clearly on actors
“Ballyhoo” – spot instruction which means for each spot to criss-cross audience area in figure eight pattern or swirl
“Pan” – going back and forth through group of actors; used often on curtain calls

13. Moving Lights have ability to move under own power
-pan, tilt, change color, change beam angle, change/rotate gobos
dichroic filter: prismatic device that changes white light to different colors by tilting angle of filter to pre-determined setting for that color
two basic styles: one complete moving piece (not able to go 360 degrees), use of a mirror to move light beam
Moving Lights

14. Plug instrument into nearest circuit and record on plot
“two-fering” – (two for one) using a twofer cable with one male end and two female ends, connecting lights together
“jumpers” – extension cords used to connect pigtail of lighting instruments
all cable should be fastened to batten with tie line
Boom: Metal structure used free-standing to hold lights; mostly used side stage to send light from wing space
Hanging the Lights

15. Troubleshooting If light fails to come on when patched into circuit:
unplug light and replace an adjoining light known to work
Replace lamp
fidget with lamp (while light of OFF)
Bumpers – section of flat iron bar bent into a circle 18”-20”
in diameter to keep lights from knocking one another out of focus
Side Arm – used to attach lighting instruments that will not fit on pipe in normal way
Troubleshooting

16. Requires minimum of 2 people: one to focus the instrument, one to run the light board
Begin at one end of an electric and move down
Focus “hot spot” to desired location on stage by locking all bolts in place
Beam Area: center portion of cone of light where the intensity is at least 50% of maximum
Field Area: the “whole beam of light”
Tilting – up/down movement
Pan – side/side movement
Ellipsoidal requires some shutter cuts
sharpen/loosen the focus by moving the barrel
shutters will mask sections of light
“flag” the light – motioning hand or foot in front to make beam flash on/off
donut – black metal sheet that fits into gel holder spot; has 2” diameter to cut out ambient light
Focusing