Lightlab: Instruments
FRESNELS
PAR CANS
ELLIPSOIDALS
FOLLOW SPOTS
SCOOPS
STRIP LIGHTS
BEAM PROJECTORS
CYC LIGHTS
COMMON LIGHTING INSTRUMENTS
FRESNEL
A fresnel is a versatile, compact, light-weight, and reasonably inexpensive lighting instrument. Excellent for top light, backlight, and general washes.
 
A fresnel lens maintains the curvature and prescription of a large convex lens in a much thinner version. The curve is stepped back towards the flat side at regular intervals. This is less expensive to produce and allows more even heat distribution through the glass, protecting the lens from expansion and contraction. The trade-off is a fuzzier, softer field.

LENSES REFLECTOR FIELD HOUSING

1 Fresnel lens
(as described above)

Spherically shaped reflector. Soft edge with extreme capacity for flooding and spotting - this means it can be very wide, or very narrow. Housing style varies slightly. In many theatres, these may be very old lights, as they last a long time.   The body shown here is very typical.
HOW SIZE IS DETERMINED ACCESSORIES
Typical sizes are 6", 8", and sometimes 12" fresnels.   This refers to the diameter of the lens.   You cannot put gobos into this, and it has no shutters.  However, you can eliminate spill and shape the light coming out using barn doors, or top hats.
PAR CAN
(parabolic aluminized reflector)

The body of a par can is nothing but a metal shell for the lamp, which includes lens and reflector within it.
 
  A parabolic reflector produces a narrow shaft of light The glass over the front of the lamp is divided into cells, which spread the shaft sideways.

A par lamp is a lot like a car headlight.  By putting different versions of the lamp into the instrument, the beam can be wide, medium, narrow, or very narrow.

By turning the lamp, the orientation of the field can be set however desired.

LENSES REFLECTOR FIELD HOUSING
The lamp has the reflector and the lens built right into it.  The texture spreads the light sideways.

Different types of lamp include:
WFL=WIDE FLOOD MFL=MEDIUM FLOOD NSP=NARROW SPOT
PAR Cans have a soft edge, but still create a clearly defined area of light on stage.  They are softer than an ellipsoidal, but sharper than a fresnel.   No spot or flood adjustment is possible.   In order to change the spread of the light, you have to put a different type of PAR lamp into the unit. 
The housing style shown here is typical.   The housing has no real effect on how this unit works.
HOW SIZE IS DETERMINED ACCESSORIES

Diameter os the lamp, measured in one-eighths of an inch.
A PAR64 is 64/8" in diameter, or 8".
A PAR56 is 56/8", or 7".

Like a fresnel, PAR Cans only use barn doors and top-hats.   No gobos, irises, or shutters can be installed.
ELLIPSOIDAL REFLECTOR SPOTLIGHT
(ERS)
Ellipsoidal reflector spotlights do a lot, and can be very percise.  They can accept gobos and irises, and have built-in shutters for shaping the field.

Ellipsoidals require a degree of maintenence and finesse; they are less easy to use than other types of instrument and are a bit more expensive.


The distance between the two lenses is adjustable by sliding the barrel, allowing good control over the field.

LENSES REFLECTOR FIELD HOUSING
2 PLANO-CONVEX LENSES; ONE IN MAIN BODY, ONE IN BARREL FACETED ELLIPSOIDAL-SHAPED REFLECTOR. HARD EDGED; MAY BE SOFTENED BY PUTTING BARREL OUT OF FOCUS HOUSING STYLE VARIES. SHOWN HERE IS A TRADITIONAL AXIAL STYLE. THE BOX-STYLE IS VERY TYPICAL OF NEWER UNITS.
HOW SIZE IS DETERMINED ACCESSORIES
WIDTH OF LENS x FOCAL LENGTH, OR FIELD ANGLE
EXAMPLES: 6x9 ELLIPSOIDAL HAS A 6" DIA. LENS AND A 9" FOCAL LENGTH. A 20 DEGREE ERS HAS THE SAME FIELD ANGLE.
SHUTTERS ALLOW SHAPING OF FIELD.
TOP-HATS MINIMIZE SPILL.
DONUTS SHARPEN FOCUS EVEN FURTHER.
GOBOS (OR PATTERNS) ALLOW EXTREME CONTROL OF FIELD SHAPE AND QUALITY.
COLOR FRAME.
FOLLOW SPOT
The most commonly know instrument. Follow spots are used to highlight and follow a single performer onstage. They require a certain amount of skill to operate smoothly. Followspots typically have a variety of colors that can be inserted with the flip of a lever, as well as a gate, dowser, focus control, and an iris.
Iris
Gate
Dowser
Focus
LENSES REFLECTOR FIELD HOUSING
USUALLY TWO STEP LENSES (DIFFERENT THAN A FRESNEL LENS; STEPS ARE ON THE FLAT SIDE) VARIES; SOME UNITS; SOME USE AN MR16 LAMP WHICH INCLUDES REFLECTOR IN IT. SMOOTH CONTROL OF RANGE FROM VERY SOFT TO VERY CRISP.
MEDIUM WIDTH TO NARROW .
HOUSING STYLE VARIES SLIGHTLY. BODY SHOWN IS VERY TYPICAL.
HOW SIZE IS DETERMINED ACCESSORIES
USUALLY REFERRED TO BY MAKE AND MODEL ONLY. MULTIPLE COLOR, GATE, IRIS, DOWSER, SPECIFICS OF EACH AND MECHANICS VARIES.

SCOOP
(ELLIPSOIDAL REFLECTOR FLOODLIGHT)
Scoops are lensless instruments, most commonly used as worklights. They have an extremely wide field angle ranging from 90 to 120 degrees.

LENSES REFLECTOR FIELD HOUSING
NONE. LARGE ELLIPSOIDAL REFLECTOR WHICH DOUBLES AS HOUSING. WIDE WITHOUT DEFINITION. SOME SCCOPS HAVE FLOOD AND SPOT SETTINGS. CRISP FOCUS IS NEVER AN OPTION.
HOUSING AND REFLECTOR ARE TYPICALLY ONE PIECE.
HOW SIZE IS DETERMINED ACCESSORIES
DIAMETER OF REFLECTOR IN INCHES.
(18" SCOOP HAS AN 18" DIA. REFLECTOR)

COLOR FRAME ONLY.

STRIP LIGHTS
are units with multiple lamps which, through color and control, allow new colors to be mixed. Strip lights are good for lighting cycloramas and are used effectively as top light.
On cycloramas, strip lights can be used alone or in conjunction with cyc lights.


Strip lights are wired so that a single electrical circuit can control a single color. In a three-circuit strip it would be quite normal to have red on the first circuit, blue on the second, and green on the third. (In lighting, the primary colors are red, blue, and green.)
 
The optimum throw distance for strip lights
onto a cyclorama is about six feet . When
they are too close, the individual fields
become distinct, and color mixing is lost.

LENSES REFLECTOR FIELD HOUSING
NO LENSES. SOME USE PAR LAMPS, SOME USE FLOOD LIGHTS, OTHERS USE STANDARD LIGHT BULBS.
SOME USE LARGE COLORED GLASS DOMES, CALLED ROUNDELS, INSTEAD OF TYPICAL COLOR.
N/A SOFT EDGED. OVERLAPPING FIELDS MIX TO PRODUCE DESIRED COLOR.
LONG RECTANGULAR BOX, TYPICALLY SIX OR EIGHT FEET LONG.
HOW SIZE IS DETERMINED ACCESSORIES
LENGTH OF UNIT. USUALLY NUMBER OF CIRCUITS IS ALSO SPECIFIED. (8' STRIP, THREE CIRCUIT) COLOR FRAMES OR ROUNDELS.
BEAM PROJECTOR
Beam projectors are inexpensive, lenless instruments good for creating shafts of light in fog or haze and across cycloramas. They can be used for general stage lighting, but their uneven field usually leaves this function to other types of instrument.
 

LENSES REFLECTOR FIELD HOUSING
NONE. PARABOLIC REFLECTOR. UNEVEN, LUMPY FIELD. NARROW.
MAY BE FLOODED OR SPOTTED. BEAM MAY VARY FROM 8 DEGREES TO 15 DEGREES. FIELD MAY RANGE FROM 8 DEGREES TO 25.
CYLINDER. VARIES BETWEEN MANUFACTUERS.
ACCESSORIES
COLOR FRAME ONLY.
HOW SIZE IS DETERMINED
USUALLY NOT REFERRED TO. SOMETIMES DETERMINED BY DIAMETER OF OPENING IN INCHES.
CYC LIGHT
A cyc light is an instrument specially designed for lighting cycloramas. They serve one of the same functions as a strip light. Their reflectlor, however, shapes the field in such a way that the cyc is illuminated as brightly at the bottom as it is at the top.
Cyc lights are frequently used in sets of three cells, with a different color in each, allowing color mixing. Twelve single cell units might be hung with red, blue, and green in them alternating, with all of the reds controlled together, all of the blues, etc.

LENSES REFLECTOR FIELD HOUSING
NONE. VERY SPECIFIC SHAPE.
NOT A STANDARD GEOMETRIC SHAPE.
BEAM AND FIELD ARE RECTANGULAR, ABOUT 100 DEGREES EACH WAY. EXTREMELY EVEN, SMOOTH FIELD. SEE DIAGRAM AT RIGHT. HOUSING STYLE VARIES SLIGHTLY. BODY SHOWN IS VERY TYPICAL.
HOW SIZE IS DETERMINED ACCESSORIES:
COLOR ONLY.
AVAILABLE IN ONE CELL (SHOWN), TWO CELL, AND THREE CELL VERSIONS.


 

Created and maintained by Matt Kizer with Plymouth State University. mkizer@plymouth.edu


Color Lab Gobo Lab Dance Lighting Light Lab Home Home