 Exposure Limitations
Hello,
I'm just wondering what the maximum size of screen I should be burning with my bulb would be.
I've got a home-build unit that uses a 1000w metal halide bulb (5000k) and a vacuum sealing top. Right now I'm burning my 23x31" screens from about 25" away. I'm not sure why I built it that size - maybe the bulb should be farther away.
My question is just at which point does the screen stop exposing around the edges? In theory, could I build a unit that was 12'x12' and use this bulb? I understand it would take longer to burn, but would it get to a point where the centre of the screen would be over exposing before the edges are properly exposed? I suppose the ratio of distance from the bulb between the middle and edges of screen will always be the same so long as the distance of the bulb increases proportionately to the size of the screen?
Thanks for any advice,
paul | 
