posted May 08, 2011 02:26 PM
Den, does your projector use a XENON bulb or ELC bulb? That is asking a lot for an ELC using a f1.6 lens. Is there any ambient light that may interfere? Try a trial projection run before you invite a crowd to see if the image would be adequate.
I was told my old 1000 watt XENON was not enough for that distance...I don't know how true it is/was being I couldn't get private use of the drive-in anyhow to test it.
posted May 11, 2011 04:00 PM
FWIW, I've seen some discussions about lumen output/throw distance/screen sizes on Film-Tech, which is largely populated by actual techs and projectionists (in addition to being the parent of this forum). Whether true or not, I have repeatedly read that throw distance is far less important than screen size in calculating required light output to achieve satisfactory results, which are defined generally as 16 footlamberts. By this theory, while the efficiency of the lens and the gain of the screen bear on the question, the total throw distance is less of a factor. Pay your money and take your choices!