How to light cyc without border curtain line

[robinwn]

I have a new lighting designer and when he focuses lights, he always has a shadow line near the top of the cyc created by a border curtain. What can I tell him to avoid this and still get the cyc fully lit?

[sk8rsdad]

It would be nice to know what lighting inventory you have available, the rigging options available, and the desired effect on the cyclorama. The only way* to avoid casting a shadow is to not have any object between the light source and the place it is trying to light. That means one or more of:

• lower the light source
• raise the border
• move the light source upstage of the border
• install a ground row
• sidelight rather than top light the cyclorama

* I suppose it is theoretically possible to hang a black hole somewhere to bend light around the border but the rigging required to support the near-infinite mass eludes me.

[jglodeklights]

Sk8rsdad is 100% correct in his suggestions.

If you need to light the CYC from an above position, your only options are to raise the border above the CYC, lower the CYC lights or move them US of the border. We haven't yet learned to how to make light bend without some intermediary object such as a mirror or prism.

Move the CYC US is the best solution overall because then it can not spill on that border either. If the problem with that is then too close a proximity to the CYC for even lighting, a more opaque diffusion gel such as Rosco 114 or Apollo 1500 may be useful in evening it out and improving blending between colors/units. My favorite strong diffusion is the Apollo 1500 because it distributes light to around 170 degrees, but still allows a hot area to peak through, important when using sky CYC units because they rely on the hot area hitting the lower part of the CYC for even illumination.

[CSCLD]

All of these are good suggestions.. However, I think that the best and cleanest option if possible is a bounce.

[65535]

Sk8rsdad is 100% correct in his suggestions.

If you need to light the CYC from an above position, your only options are to raise the border above the CYC, lower the CYC lights or move them US of the border. We haven't yet learned to how to make light bend without some intermediary object such as a mirror or prism.

Move the CYC US is the best solution overall because then it can not spill on that border either. If the problem with that is then too close a proximity to the CYC for even lighting, a more opaque diffusion gel such as Rosco 114 or Apollo 1500 may be useful in evening it out and improving blending between colors/units. My favorite strong diffusion is the Apollo 1500 because it distributes light to around 170 degrees, but still allows a hot area to peak through, important when using sky CYC units because they rely on the hot area hitting the lower part of the CYC for even illumination.

Truth be told light bends around every object to some extent.

Anyways, we've always had the 4th Electric (Cyc wash) US of the last border, works perfectly every time.

[shiben]

Truth be told light bends around every object to some extent.

This is true. Light is affected by the gravity of all objects, including you and the border (and the atoms in the air). However, its only really an observable effect when the object bending the light is the sun.

[65535]

Or diffraction gratings...stupid physics lab.

[Syphilis]

I'd agree we need to know more about your theatre, rigging situation, and available fixtures. But just right off the bat, if there's a soft good in between the light and the cyc, there'll be a shadow. If there needs to a teaser in front of the cyc, to cover the batten or something, then the most obvious solution would be backlighting the cyc (which might also require a ground row).