The SeaChanger Color Engine is an electro-mechanical device that is used to control light color in entertainment-industry lighting

Lighting

Lighting or illumination is the deliberate application of light to achieve some practical or aesthetic effect. Lighting includes the use of both artificial light sources such as lamps and light fixtures, as well as natural illumination by capturing daylight...

 applications. The unit employs four overlapped color filter wheels, inserted into a light beam near its source, to produce colored light. This is in contrast to color scroller

Color scroller

A color scroller or color changer is an electro-mechanical lighting accessory used in theater, film, dance and concerts to change the color projected by stage lighting instruments without the need of a person to be in the vicinity of the light...

s, which insert color filter ribbons into a light beam. The color engine, which was released by Ocean Thin Films in 2005, is designed to fit into the Source Four

Source four

The Electronic Theatre Controls Source Four is an ellipsoidal reflector spotlight used in stage lighting. First released in 1992, the Source Four features an improved lamp and reflector compared to previous ERS designs, tool-free lamp adjustment, and a rotating, interchangeable shutter barrel...

 lighting instrument made by Electronic Theatre Controls

Electronic Theatre Controls

Electronic Theatre Controls is a privately held corporation with global headquarters in Middleton, Wisconsin, United States. An international manufacturer of entertainment and architectural lighting systems, ETC offers professional lighting fixtures, lighting control consoles, dimming equipment...

.

Technology

The SeaChanger Color Engine is designed to fit between the reflector assembly and lens barrel of a Source Four ellipsoidal, replacing the gobo slot and accessory slot. It is designed to be installed without tools.

The unit is available in profile and wash versions. The profile model uses the lens barrel and reflector assembly of a Source Four, while the wash model uses only the reflector assembly. The manufacturer provides a lens assembly for the wash unit. There is also a high-intensity discharge lamp

High-intensity discharge lamp

High-intensity discharge lamps are a type of electrical lamp which produces light by means of an electric arc between tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina arc tube. This tube is filled with both gas and metal salts. The gas facilitates the...

 (HID) model available wherein only the lens barrel from the Source Four is used in the profile fixture. The wash version of the HID fixture is a completely stand alone unit, not using Source Four components at all, although the same color engine technology is used.

The color engine contains integral power supply and communication interface. The unit is mounted in the iris slot of the Source Four fixtures, meaning that it is placed directly in front of the source, or lamp and before any optics or beam shaping devices. Inside the unit, four micro-lithographed dichroic filter

Dichroic filter

A dichroic filter, thin-film filter, or interference filter is a very accurate color filter used to selectively pass light of a small range of colors while reflecting other colors. By comparison, dichroic mirrors and dichroic reflectors tend to be characterized by the color of light that they...

s are gradually saturated from 0-100%. Wheel colors are standard CMY

CMY

CMY may refer to:*Sparta/Fort McCoy Airport in Sparta, Wisconsin*CMYK color model...

, having one wheel each for cyan, magenta, and yellow, as well as one green wheel. The SeaChanger profile is unique in that its green color filter increases its color gamut to include deep blues, reds and greens that are difficult to create through dichroic color mixing. The green wheel may be replaced with black for mechanical dimming purposes in HID fixture applications or other applications where dimmers are not available. Stepper motor

Stepper motor

A stepper motor is a brushless, electric motor that can divide a full rotation into a large number of steps. The motor's position can be controlled precisely without any feedback mechanism , as long as the motor is carefully sized to the application...

s turn each of the wheels to create colors, with wheel position and speed controlled by a four-channel DMX512 or RDM

RDM (lighting)

Remote Device Management or RDM is a protocol enhancement to USITT DMX512 that allows bi-directional communication between a lighting or system controller and attached RDM compliant devices over a standard DMX line...

 signal from a lighting console.