As my mouldings to fit LED to lens are egg-cup shapes , a 3 part mould
required, letting epoxy harden before running off 7 of them, so far so good.
I was impressed with just trying one LED at 1/4 power of 90mA (no
heatsinks yet) and 5 feet away , bright enough to read by just.
Add a lens at the correct position and a neat bright foot by foot
"pixel" , of the chip thrown on a screen 5 foot away, probably as bright
as the projector showing white (DLP losses unknown).
So 7 of them and 4 times as bright would illuminate a 5 x 4 foot screen
, with that brightness. If 50% loss in hte projector then add another
ring of 6 , room in the "funnel" reflector for them if required.
I wonder what a gobo type thing made of a matrix of single RGB LEDs ,
with lens arranged to throw foot x foot squares with 6 inch overlap ,
would look like if driven with graphical/animated "video" pulses