As LED fixtures have become more and more common in lighting rigs, these color changing devices have mostly gone the way of the dinosaur. I will give a quick overview of these devices in case you come across some in an inventory someplace. Very soon, if not already, these will be considered obsolete.
color scrollers
A color scroller is a device that allows the designer at the lighting console to choose the color of the instrument in which the scroller is installed. All color scrollers work by the same general mechanism. A long polyester gel-string is attached to two rollers, which wind the gel to the proper location for the selected color.
Most color scrollers have a set number of 'frames', often 16 or 17. Each frame is a separate color. Most gel companies and some scroller manufacturers will sell pre-packaged gelstrings (such as is seen below), or custom strings can be specified and ordered through theatre suppliers. |
There are a few scrollers that work on a CYM color mixing principle. The Wybron CXI works by having two scrolls that instead of having separate cells of color, it instead has a gradient from clear to heavily saturated secondary colors. This way, by setting each of the scrolls to particular spots along the string, almost unlimited color possibilities exist.
In all cases, the scroller works on a separate DMX address from the intensity channel of the fixture, effectively making an instrument with a scroller into a multi-attribute device.
In all cases, the scroller works on a separate DMX address from the intensity channel of the fixture, effectively making an instrument with a scroller into a multi-attribute device.
Seachanger
A company called Seachanger is manufacturing several dichroic based color changing systems, both as full instruments, and as accessories that can be built onto ETC Source 4 fixtures. These work in the same way as CYM color mixing in moving lights. There are 3 or 4 dichroic glass discs that have a gradient of each of Cyan Magenta and Amber, and sometimes an extra Green.
Because these color changing engines are based on dichroic glass, the colors can be much more saturated than polyester gel. They will also last a lot longer. Of course, the cost reflects this... |