Term
| What are the parts of a lamp? |
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Definition
| An envelope, a filament and a base. |
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Term
| Why can’t you touch the envelope of a lamp with your fingers? |
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Definition
| The envelope in an incandescent lamp reaches very high temperatures that glass would not be able to withstand, thus it is made of quartz. Oil found on the fingers will penetrate the quartz. Sometimes the lamp will stop working other times it might violently explode. When changing a quartz lamp use the plastic or foam sleeve the lamp comes in to keep from touching the envelope. |
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Term
| How are lamps classified? |
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Definition
| Each lamp we use is designated by a three-letter ANSI code, these lamps are described by their shape, size, wattage, voltage, color temperature, average life and filament design. |
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Term
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Definition
| Ellipsoidal reflector spotlight |
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Term
| What type of lens is used in an ERS? |
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Definition
| Two plano-convex lenses arranged in a belly-to-belly configuration are mounted in the barrel and can be moved to create a hard or soft edge to the spot of light. |
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Term
| Where in the optic train of an ERS are gobos and shutters placed? |
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Definition
| They are placed at the gate. |
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Term
| What are ERS fixtures commonly used for? |
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Definition
| The ERS is commonly used as a front or key light for an area since it produces a sharp edged controllable beam of light that can be shuttered off curtains or the architecture around the stage. Other uses of the ERS are as specials, wash lights, pattern/effects projectors and follow spots. |
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Term
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Definition
| Bench focusing is a way to adjust the field of light that comes out of the fixture. Some designers like a flat field where the intensity of light is equal across the beam while others prefer a peak field where there is a hot spot in the center of the beam. |
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Term
| What is special about the Fresnel lens? |
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Definition
| The Fresnal is named after the lens itself instead of the fixture as with the ERS. A signal fresnal lens with a textured back is used to diffuse the light emitted from the fixture. |
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Term
| What type of light is produced by a Fresnel? |
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Definition
| The Fresnal light produces diffused light. The fresnel fixture is primarily a wash fixture with a soft edged beam that allows multiple fixtures to be blended together to create a broad, even field of light on a stage. Fresnels can be used as soft focused specials but their true value is as sculptural light from the back or top. |
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Term
| How do you create a large pool of light from a Fresnel? |
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Definition
| The lamp and reflector assembly can be moved closer or farther from the lens to increase or decrease the beam size, but other than that there is not much beam control on a fresnel. External shutters called barn doors can provide some beam shaping ability, but it is not as precise as what you can achieve with an ERS. |
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Term
| What type of reflector is used in a Fresnel fixture? |
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Definition
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Term
| What is a Fresnel commonly used for? |
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Definition
| The Fresnal is used in theater for acting area lighting where beam shaping is not required or in television studios for key and backlighting. |
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Term
| What type of lamp is used in a Par Can? |
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Definition
| The most common types of lamps are: very narrow spot (VNSP - "vee-nisp"), narrow spot (NSP - "nisp"), medium flood (MFL - "miffle"), and wide flood (WFL - "wiffle"). In addition to the type of lamp, PARs come in several sizes, denoted by a number (typically one of 16, 38, 46, 56 or 64). |
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Term
| What type of reflector is used in a Par lamp? |
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Definition
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Term
| How do you focus a Par Can? |
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Definition
| Focus of a conventional par consists of rotating the lamp to change the orientation of the concentrated oval in the center of the light beam. |
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Term
| What are the designations of Par lamps? |
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Definition
| Par16, Par38, Par46, Par56, Par64 these designations denote the size of the can and the lamp. |
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Term
| What are Par Cans typically used for? |
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Definition
•Wash lights
•Sealed beam reflector lamp
•Parabolic Aluminized Reflector
•Oval Beam – Down Light and Side light |
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Term
| What type of lights would you use to light a back-drop? |
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Definition
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Term
| What is a strip light used for? |
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Definition
•Broad wash
•Multi-circuit
•Color mixing |
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Term
| What type of reflector is used in a CYC light? |
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Definition
•Asymmetrical reflector
•Spread reflector
•Backdrop Lights |
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Term
| What is the optimum throw distance for a CYC light? |
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Definition
| Cyc lights are designed to be hung 8’ away from the drop on 8’ centers, this will ensure that even coverage is achieved over the whole drop. |
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Term
| What is special about the ETC Source 4 when it comes to heat dispersion? |
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Definition
| One of the major improvements in the Source 4 was the use of a cold mirror reflector and an HPL-575 lamp. The lamp has a build it heat sink and this, along with the reflector, causes most of the heat produced by the fixture to be dissipated out the back rather than through the optic path with the light. |
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Term
| What type of lamp is used in an ETC Source 4? |
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Definition
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Term
| What shape of beam do you get from an ETC Source 4 VNSP or NSP par? |
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Definition
| VNSP and NSP configuration will produce a round beam of light instead of the traditional par can oval. |
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Term
| How do you focus a follow spot? |
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Definition
| A follow spot has shutters for beam shaping but unlike an ERS, there are normally only 2 shutters that operate concurrently to cut off the top and bottom of the beam. An iris allows the operator to change the size of the beam and a dowser enables fading. |
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Term
| What three types of light sources are found in follow spots? |
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Definition
| Follow spots can be classified as long throw, medium throw and short throw fixtures. |
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Term
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Definition
| A set of external shutters that mount in the gel holder of a fixture and are commonly used in Fresnels, can also be used in PAR fixtures. |
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Term
| What is a top hat used for? |
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Definition
| A device used to hide lens flair that can be mounted in the gel holder of a fixture. |
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