If of more help, here might be more info on where to go next steps, and another solution - rear projection. Also got me generating more thoughts now on how I might do it on the cheap from the rear projection as a better solution yet if you have the depth of
stage and scene shop.
First on the custom gobos, these will be custom so I would recommend you get your
gobo/
gel supplier vendor rep. out to your location ASAP, and perhaps hang a
drop or do some form of plywood or office space wall where your rainbow will be located. Just a solid upstage wall to measure from. In the show, a
flat cyc or wall to project on would than be best if script doesn’t require talent to go upstage of it which is a further problem also with the below concept.
On projecting the
image, (
Apollo and
ETC help here) there will be very specific angles and measurements that will be needed to figure out in designing the
gobo - too large a projection for just one
gobo unless say a very wide focus
Leko rented could do it... but I have no idea how well it might project the
image. This is something your vendor rep. is paid to know or figure out. In other words, what’s the widest beam spread
current to a S-4
Leko and how well can it project a rainbow on your size of rainbow? Can you get it into a hanging position even with side arm so as to attain the
throw distance? I would assume a single
Leko projecting the
image would be the most viable solution and actual dimensions of the arc can be downscaled a little, or if you do two or more projections, how well do they match up
thru the run in perhaps needing a re-focus, but might be necessary. After that a question of in getting that beam spread, at what angle is it in talent moving about the
stage this projected
image effecting for potentially needing more lights to project it?
Will take specific measurements and math to figure out the exact
gobo to use, one
dichroic for the colors, than another perhaps cheaper metal for gelling after for the solid colors. Your vendor rep. again is the best person to help design this
gobo once location of the
Leko(s) is determined. Dichroics will pop better but other than for the rainbow which will probably be necessary, simple
gel in the frames would work.
Onto the other idea:
Don’t know when you need to be solid color verses rainbow in the show’s needs, but if you have the upstage space of say a few at least four feet or more to shoot at the rainbow from the rear, it might solve problems of projecting the
image properly or talent shadowing the
image.
Consider instead of a light box, one similar to above channeled for the six colors but with an open back and front. Tough to fabricate but possible six parallel arches to make. I’m thinking sheet metal/flashing inner louvers and plywood outsides for structure. Smaller in depth sheet metal/flashing spacers to keep the sheet metal parallel. The spacers would need to be flush to the rear and have a small
bend on their rear so as to mount the most economy
velcro you can get, than dirty the
Velcro up.
Build an upstage wall around the arch so stray light doesn’t get out from upstage other than
thru the rainbow.
Velcro the plywood arch outer walls on the rear also. Dirty it up also so it doesn’t stick well in holding too much for sufficient for easy removal, but sufficient to hold
gel hung on it. A heat gun might be able to do this most easily but R&D would have to be done in perhaps a sander with fine grit would work also. You now have the rear of the light box able to mount a large arch scroll of
gel’s - the rainbow or solid colors which once cut and taped together would get the reverse side of the
Velcro. You tend especially on
Velcro to wood and metal to want to add a better
epoxy or super glue spot of glue to it in reinforcing the adhesive of the
Velcro. Something that especially on end grains of plywood would sink into the end grains for holding. Pneumatic M
crown staple reinforce also so it sinks in but has a large enough surface area to prevent tear out on the plywood.
Would take ambition and a decent metal worker to make the spacers on a bench vise, lots of rivets
etc. Can be done as a concept. No idea of how much
gel it would take, but you make rolls of arch
gel to
velcro to the rear of the light box for what color or colors it will be.
Roll on/
roll off would now be the challenge. If
blackout between scenes and a fly
system... think it’s an Olieo upstage you would bring down between upstage and
downstage so as to let the lights upstage allow
stage hands to
gel change between scenes to be rolled out or removed.
That’s where you need at least a 4' gap between true upstage and the new wall. At least 2' for a
PAR 64 wide focus to be mounted on a arched
arbor at about 45 degrees lower or higher to the light box, and some room for beam spread and
stage hands to change
gel. 45 degrees or so you minimize hot spots, I would go higher in angle rather than lower in considering the audience and mounting
So now you have a rear projection of what ever
PAR 64 wide figured on, but really what ever you have or can get light out of in your now upstage light box. Change rear gels to change the color given the light box channels. Ton of
PAR 38 or what ever including
fluorescent lights store bought as long as you get a high
CRI. Such lights would be useful otherwise and save at least 12" of room upstage. Keep the arc curve in projection, though flourescents in already frosted would want direct projection as possible.
Ok... long above, got the rear
gel done but have not addressed the front of the rainbow. As described above, could
gel it, could white plexiglass or other medium of plastic do it. White in plastic for some reason seems to work best over
frost I have tried many times in R&D. White painted for all louvers and interior parts. Lenses and interior white. Simple spraying day if doing so also for the front
lens.
One could Suran wrap or
pallet shrink wrap the entire front
lens of this light box if furring strips to keep it the structure in ready to ready to do. Apply and attach so it dont'
peel off. This with perhaps glue of some sort. Something to keep this
clear but stretchable front
lens stretch to the arch material from coming loose. Than once the
clear lens, could simply spray paint or paint the plastic
lens white - front or rear, shouldn’t matter but I would R&D that. Scrap
scrim or thin drapery material could also work in passing the colored light. .
Presented is a concept in if you have upstage room, might be able to do this.
PS. if say a
PAR 64 or other
gel frame
fixture projecting light, you perhaps only need to have a rainbow
gel scroll to mount or remove. Can just
gel the lighting fixtures also in gaining that solid color to the arch/rainbow.
