Pre-Focus scoop bases? Fascinating.
A Lienbacher
projector is all about the
filament - focal center of the
point source of the
filament in relation to the projected
image.
Black wrap the
reflector so as to reduce double and odd images and you now have the single
filament point source
projector at a less efficient state. Possible your
reflector will be re-focusing sufficient but doubtful short of a
gate the size of your
filament.
In doing the projected
image, you are trying to have what’s a parallel or
point source of beam come out of the
image.
Cover the
reflector, you now have this. Next is all about focusing the
image of the slide to that of between the set and
image plane or slide. Also a really graphic slide.
Once you get this distance and
play in focusing it, lock down the slide at that distance and done, the
scoop now a
projector. Mask off the stray light. You will no doubt need like a 36"
lens train to do so and a 24" slide or larger if sizable the
image.
Back in my day I did so out of some Century 8x9 fixtures which were once
reflector and
lens train removed about similar to a 14"
scoop in size. Worked well with a large sheet of acrylic plastic that was painted with an
image. No worry about heat, the
image plane was far too remote from the
projector. Much harder to mask the stray light and affix the panel to the
fixture than any heat issues on the plastic with latex paint on it.
Final note or curiosity is what wattage the scoops are? If under 1Kw, in expecting about half the normal
intensity, you will have problems. If 2Kw, you are probably golden.