E llipsoidal
R eflector
S potlight
ERS fixtures can also be referred to as "profile fixtures," "Leko," "ellipsoidal," or just by their degree.
Fixture Overview
An ellipsoidal reflector spotlight fixture, or ERS, is named so because it contains a reflector that is ellipsoidal in shape and can create a spotlight beam of light. The reflector in the ETC Source Four fixture has a textured surface to help with the reflection of light. As with the PAR and fresnel fixtures, the shape of the reflector helps determine the spread of the beam before reaching the optics of the fixture.
An ERS is a spot or profile fixture with a crisp, evenly distributed light with a hard edge. The ability of the fixture to create this sharp, well-defined beam edge, and shaping this beam is what makes this fixture one of the most used fixtures in the industry. The hard edge can be softened by adjusting the lens barrel or the use of frost to make the pools of light blend seamlessly together. The shape of the beam can be controlled through the use of internal shutters or by placing a template in the fixture. The spill light from these fixtures is very minimal. The beam of an ERS fixture is dependent on the lens installed, but can be very narrow, allowing for a further throw of light.
An ERS is a spot or profile fixture with a crisp, evenly distributed light with a hard edge. The ability of the fixture to create this sharp, well-defined beam edge, and shaping this beam is what makes this fixture one of the most used fixtures in the industry. The hard edge can be softened by adjusting the lens barrel or the use of frost to make the pools of light blend seamlessly together. The shape of the beam can be controlled through the use of internal shutters or by placing a template in the fixture. The spill light from these fixtures is very minimal. The beam of an ERS fixture is dependent on the lens installed, but can be very narrow, allowing for a further throw of light.
All Degenstein theatre fixtures have an inventory number and barcode for inventory and maintenance purposes.
Fixture DegreEs & Color Coding
(Specific to SU only)
Lens barrels at SU are numbered for inventory purposes. (Click on degree for datasheet)
Beam Characteristics
Size - Dependent on lens and sharpness of focus. Some fixtures may have zoom capabilites.
Shape - Circular. Can be shaped by shutters, patterns, and irises.
Intensity Distribution - ranges from flat-field to hot-spot. Dependent on lamp alignment.
Edge - Sharp, but can be softened.
Shape - Circular. Can be shaped by shutters, patterns, and irises.
Intensity Distribution - ranges from flat-field to hot-spot. Dependent on lamp alignment.
Edge - Sharp, but can be softened.
Fixture Parts
From the ETC Source4 User Manual
C-clamp - used to attach the fixture to a pipe
Pigtail - cable that runs from the lamp housing to the fixture plug. Barrel rotation knob - used to adjust barrel when using shutter cuts Reflector housing - contains the ellipsoidal reflector and the yoke attaches here Safety cable - required for all fixtures, must be attached around pipe Shutters - used to help shape light during focus Beam focus knob - loosen (does not need to be removed) to adjust focus of the beam (sharpen or soften) Barrel assembly - houses the shutters, lens barrel, pattern slot, and iris drop-in slot. Lens barrel - interchangeable barrel to change field angle of fixture. Can be adjusted to give the beam a soft or sharp edge. Stage pin plug - used to plug the fixture into the circuit. Flat connector often referred to as pin connector or two-pin and ground connector. |
Yoke - U-shaped bracket that supports and attaches the fixture to a pipe/batten via the c-clamp. Allows for panning and tilting of the fixture during focus. Lamp housing assembly (Lamp burner) - contains the fixture lamp. Pigtail comes out of the assembly. Contains knob to center the lamp (bench focus) to adjust the field. Yoke locking knob - loosen to adjust the tilt of a fixture. Pattern holder slot - slot to drop in pattern (gobo), should always be at the top of the fixture Drop-in iris slot - slot to drop in an iris, glass pattern, or other accessories. Cover should cover slot when not in use. Gel retaining clip - used to hold the color frame and other accessories in place Color frame holder - two slots to place color frame and other accessories on the fixture. |
Pan bolt - used to adjust the side-to-side focus of the fixture.
Pipe bolt - used to secure the c-clamp to the pipe. Yoke bolt - attaches the yoke to the c-clamp. Can be used to adjust the side-to-side focus of a fixture. This is the preferred bolt to adjust the pan. |
Lamp retainer wire - helps hold lamp in place
Socket assembly - ceramic piece that the lamp plugs into. HPL lamps have two or three pins. Insulated handle - useful handle for adjusting fixture during focus. Screw - brass screw that holds the lamp housing assembly (lamp burner) in place on the reflector housing. Lamp adjustment knobs - inner and outer knobs used for adjusting lamp placement inside of fixture (known as "bench focusing"). Inner knob adjusts peak/flat field and outer knob adjust lamp centering. HPL 750W 120V lamp - High Performance Lamp designed specifically for the Source Four fixture. |
Reflector
The ERS fixture uses an ellipsoidal reflector, which is half of an ellipse. An ellipse has two focal points which allows the light to be easily and sharply focused. The lamp sits in the focal point in the reflector and the second focal point is between the gate (where the shutters are).
Fixture Alignment
ERS fixtures have a "top" and "bottom."
The "top" of the fixture has the pattern holder slot, the drop-in iris slot, and the retaining clip.
Because there is no retaining device for the pattern, this must be at the top of the figure whenever a pattern is used.
The barrel adjustment and beam focused knobs should be on the bottom of the fixture. This consistency helps during focus call.
The "top" of the fixture has the pattern holder slot, the drop-in iris slot, and the retaining clip.
Because there is no retaining device for the pattern, this must be at the top of the figure whenever a pattern is used.
The barrel adjustment and beam focused knobs should be on the bottom of the fixture. This consistency helps during focus call.
Fixture Storage
When placing the ERS fixture on the meat rack, be sure that the inventory number and barcode are facing out.
Fixtures should be placed as close together as possible so that 11 fixtures fit on the pipe.
Be sure to place the fixture on the proper pipe (color coded to match the lens degree). If the pipe is full, fixtures can be placed on another pipe.
C-clamp should only be finger tight - NO need to tighten with a wrench.
Fixtures should be placed as close together as possible so that 11 fixtures fit on the pipe.
Be sure to place the fixture on the proper pipe (color coded to match the lens degree). If the pipe is full, fixtures can be placed on another pipe.
C-clamp should only be finger tight - NO need to tighten with a wrench.
Older And Other ERS Fixtures
Copyright Caleb Stroman 2023
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