This is really dependent on multiple factors, the throw distance and amount of coverage required, if you are using the back of your CYC is it 3' off the rear wall of the stage? Or a greater distance, do you want a soft or sharp image, I would recommend playing with some of your theatrical fixtures to see what works the best for you.
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Jerry Onik
V.P. Theatrical Supplies and Equipment
Heartland Scenic Studio
NE
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