fluorescent light set up

[Mark Suszko]

I would opine that to light a green screen, you really need the long straight tube style of Flo, not these twisty bulbs, because the idea is to get a wide, soft and even light. Open faced spot lights are difficult to make truly “even” on a large surface. As you’re finding out. I light my green screen with Lowel Rifa lights, works great, but if I had 12-foot tubes, I’d probably use those.

Another thing you can try with these curly bulbs, if you’re committed to them, or to use with the existing “hot” bulbs, is make some softbox attachments to the front of the Smith-Victors. Bill Holshevnikov did a great tutorial on this long ago that I adopted and use all the time. Basically, you make a soft box from trapezoidally-cut segments of foam core, ($3 at the Walgreens) gaffer-taped into a box shape, add a diffusion material to the front using thumbtacks. (I use toughspun or tuff frost or tuffopal, this will be the costliest part of the whole unit, using real diffusion, buy it by the sheet from Markertek perhaps) Mount the whole thing to the open-faced light’s barn doors with “bulldog” or “binder” clips made of metal, though wooden C-47’s would also work…

There’s a *little* more to it than that, but not much. Mostly has to do with making the width of the trapezoids a little wider than the beam that emanates from the hot halogen bulb, so it impinges less directly on the foamcore… this plus a generous air gap around the back rim of the fixture lets this thing run all day without getting even slightly warm.

I know, our CE didn’t believe it either, until I demonstrated it for four hours for him; it DOES work. The materials are dirt cheap and the unit is disposable or, if you slit one of the taped-up seams, you can fold it up to store for another day.

A Chimera or Rifa, made from your existing Smith-Victor, for under ten bucks. You can’t beat that.

[Trey Eckles]

Thanks Mark. I will try that out.

Do you think these lights will work for the interviews though.

I may stick with hot lights and get or create a softbox for the green screen shooting.

[Mark Suszko]

“Will it work” is a very subjective term. I would say, if you know something about how to light correctly, you can light with the most abysmal instruments and get away with it. For a simple one-person close-up sit-down interview, I’ll say yes, *probably* you could use them. If I was “stuck” using them I would probably still diffuse the source more, or bounce it off a reflective card. The beam characteristics of the twirled-tube Flo bulb will be different from what you’re used to from a halogen lamp.

BTW, if you’re going to build the soft box I mentioned earlier, what I do is lay the instrument on the bare concrete studio floor and turn it on for a few seconds to mark out the actual cone of the beam it emits. Then I cut my trapezoidal panels of white foamcore or gatorboard to be several degrees WIDER than that cone. Do not skip that step, or you may have problems!

[Trey Eckles]

Thanks. I will see what happens.

[Alan Lloyd]

I’d also suggest looking into white “silk” (directional) diffusion – the stuff with the fibers in it. Orient the fibers at right angles to the direction you want the beam to spread. Result: A smooth, wide beam. Costs the same as frost, which everyone also needs..

[Trey Eckles]

THANKS Where could I get the silk diffusion material from?

Which light would you buy? The 27 to 30 watts or the 55 to 75 watts?

[Alan Lloyd]

Lighting shops – your local rental house will almost always also sell “expendables” as part of their operation.

As for lamps, bluntly, using those you linked to in two fixtures on a green screen the size you’re describing is not going to yield satisfactory results. And diffusing them is not going to help much. Four fixtures would give you a much better chance of evening things out. Mark’s horizontal placement of long-tube fluoros is even better.

The most important part of greenscreen work is getting the background evenly lit. Next comes controlling bounce or “spill”. (Rim light with a touch of magenta helps.)

[Dennis Size]

To clarify:

The directional silk doesn’t have fibers in it to diffuse light. It is etched to spread the beam of light lengthwise. When using directional silk put the etching — or “grain” (which is obvious to see) opposite of the direction you want to spread your light.
For example, if you need to spread your beam of light horizontal, then your etching grain should be oriented vertically in front of the light.
The silk is made by several different color media/diffusion companies (LEE, GAM, ROSCO, APOLLO, etc), and comes in a mylar based “gel” form — available in 3 different flavors of diffusion quality. You can buy it in rolls or sheets.
I usually use the ROSCO products (either cinegel or roscolux). Their versions (and product numbers) are ROSCOLUX #104 – “Tough Silk”; ROSCOLUX #113 – “Matte Silk” (my personal favorite); and ROSCOLUX #160 – “Light Tough Silk”.
You can purchase this product from any theatrical or television equipment supplier.
As a sidenote, the diffusion with the fibers in it — is known as “Spun” diffusion (ROSCOLUX #105 – “Tough Spun”). It is a wonderful diffusion that comes in several gradients. It holds up EXTRMELY well to heat and layering, and creates an exceptional soft quality ….especially when several sheets are layered and spaced apart (one in a frame, one or two on the barn doors). There’s not a show I light that I don’t use several rolls of “Light Tough Spun” (ROSCOLUX #106).

Stay silky soft.

DS

[Alan Lloyd]

My clumsy phrasing…

Silk and spun are both my friends.

[Tom Shepherd]

Hi Mark,

Thanks for this, the DIY softbox sounds great. The only thing is that I’m having trouble visualising how the air gap works. To try and clarify a bit:

– You’re saying that the dimensions of the rear end of the soft box should be the same size as the square frame where the barndoors are hinged onto the light?

– When you attach the softbox to the barndoors, what should be the distance between the back of the softbox and the light head?

– When you clip on the box, should the barndoors be on the inside of the cone, or on the outside? Or does it matter?

Thanks a lot for your help.