Color scroller

When colour scrollers were first introduced around 1980, a number of companies produced them, including: Avolites, GAM Products, Morpheus Lights, Rainbow, Rosco Laboratories and Wybron Inc. Now the main manufacturers are: A.C.

The Apollo MXR 2, Chroma-Q Cascade and the Wybron CXI use 2 gel strings to obtain a CMY mix.

Finally, there are "true" CYM mixing scrollers that utilize three independently controlled gel strings - namely, the "ColorFader" system manufactured by Morpheus Lights of Las Vegas, NV, USA.

Colour density variation is achieved by starting with a full-density sheet of gel (or dichroic glass) in either Cyan, Magenta or Yellow.

At the zero DMX "start" position on a ColorFader scroll there is a piece of clear gel (which is perforated with large holes to maximize light transmission).

As DMX control value increases, it progresses the scroll further and the holes become smaller and less numerous - so the percentage of coloured material in the optical path increases relative to the white light pass-through, and the result is progressively higher density colour transmission.

Once addressed, the unit is then connected with other colour scrollers and run back to a power supply (typically with 4-pin XLR cable.

Head-feet is defined as the total sum of the lengths of cable from each device to a single power supply.

Because independent "Home runs" (uninterrupted connection) of 4-pin cable reliably carry power and control signal directly to each ColorFader unit, the need to keep track of "head feet" is eliminated.

Some new models of scrollers are moving towards the RDM protocol and are using small LED screens for addressing and other settings on the unit.

Most companies offer two standard types of gel strings generally referred to as "theater" and for "rock and roll".

"colourmerge" was a relatively expensive device which lacked reliability - these problem ultimately caused it to fail in the marketplace.

In 2009, Morpheus Lights introduced the PacificFader line of dichroic colour changers, which were specifically developed for use with the modular Selecon Pacific ellipsoidal fixtures manufactured by Philips Entertainment.

PacificFader4 added a smooth optical dimmer/douser to the C,Y,M control, for use with energy efficient arc sources (CDM, MSR, MSD).