Combining Point Sources

[RoberttorresDP]

Hello Roger and forum members!

I was wondering if anyone knows the effect of clustering 1200Ds, or similar sources, to create one large point source light without multiple shadows.

We are shooting on the second floor of an old barn, that has slats where light can punch through, ideally we want rays of light shining through as the sun and haze illuminating the rays as a backlight to the talent.

Ideally I would put a 12k or 18k tungsten fresnel outside of the space on a condor.  However due to budget constraints I don’t believe this would be possible.  The main problem is that we are shooting on the second floor of a barn, so without a condor any light would have to go on top of a matthews mambo combo at 24 feet, which would have to be a much smaller light than a 12k, physically.  Unfortunately a long john stand will be slightly too short and would end up too head-on.

Thus, I was thinking a lighter light such as a 1200D would work on the mambo stand.  However, that light would not be bright enough.  So, I was thinking of clustering 3 or 4 of them together to create one large point source, but I am worried about having multiple shadows in the barn.

Do you think clustering these lights would lead to multiple shadows, or is there maybe a different solution here?

Best,

Robert

Topic

[James Parsons]

If I understand correctly, you’re not trying to illuminate the interior with these lights, just blow out the spaces between the slats and let the light beams glitter in the atmosphere, correct?

I don’t know how big a space you’re dealing with, but my instinct wouldn’t be to cluster them, but to line them up horizontally, aimed in parallel, not at a single point in the set. If there’s no structural elements interrupting the gaps across the width of the wall, I guess I’d probably slightly overlap the edges of the beam spreads, try to keep the light level reasonably even left-to-right. That should keep you from getting multiple shadows.

If you really wanted to turn four bulbs into a single close source, your trickiest puzzle will be getting the heads right up next to each other if they’re each on a separate stand. You might have to get creative and invent a sturdy way to mount them safely on one or two stands. The other option of course would be to aim them all through a diffusion frame so that that becomes the source, but then you’re losing some of the punch you’re trying to build up by clustering them together in the first place.

If you’re imitating the sun, the “point source” of the sun is far enough away that all the rays are coming at you in parallel, as if from the entirety of the local sky, not from a single nearby point.

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