The "Go Fres" is of the same concept - only as a patern
projector instead of color
projector. See
USITT 3rd Blennial
Theatre Technology Exhibit 1991.
Reflector is removed or covered with black wrap as with the
lens.
AT that
point, you would if doing some form of colored
lens want a
safety glass
lens or some really high temperature
clear plastic - potentially available but not cost effective. Your local glass store could easily knock off some
safety glass lenses that would fit into the
gel frame of the
fixture. Want to
gaff tape your
lens edges so as to pad them some.
At that
point you have a
lens, you could dye it as long as the
lens is really clean, or possibly just do strips of
gel taped to it - outside the
fixture side of the glass. This or
laminate the
gel between two pieces of glass taped together if the glass is cheap enough.
Should work as a concept but you would have to tinker with the beam spread of the Go Fres as opposed to
throw direction and distance, and how refined the
image would need to be. Some Sharpee lines on the
lens between colors could also help refine the rainbow some as a theory to experiment with. Dependant upon how graphic and un-washed out the colors you wished for, you would probably need a few fixtures and they should be as close to as dead on in projecting on the
cyc as possible. Angle of projection tends to
wash out the graphic rainbow
gobo that this would be.
If the
image from the
Fresnel is not graphic enough, try the
fixture in spot position and if still not enough, try the glass
lens in a
top hat's
gel frame holder. All a question of distance and focus verses
spill messing up the
image.