For interviews, I almost always go with a diffused softbox now instead of hard lighting. Can you mount a speed ring to the redheads and hang a Chimera on at least one of them? If pressed for cash, you can make something similar with a few hours and ingenuity. Just might not be as east to set up, take down, and use. A buddy showed me one he made using the lathe in his home shop to drill angled holes into a block of aluminum. He sticks fiberglass rods from a kite store into these and they tension the four corners of a sheet of white ripstop nylon kite cloth with pockets sewn into the corners. Choice of the fabric can be tricky, ideally you want something heat tolerant. You can use a large sheet of tough spun and be pretty safe.
I have for years made a variation On Bill Holshevnikoff's foam core light box for studio work using a 1K with barn doors, binder clips, foam core, tough spun, and a little gaffer tape. Thing never gets warm even after being on for hours, but you have to make it right using the proper angles and mounting technique. Only takes about ten minutes or less to do, one of mine lasted five years. You can slit the tape and fold it up for travel without hurting anything. Used these a lot before we got our Rifa lights.
Get the barn doors and clip as many layers of tough-spun as required, letting hang in front of the light. With the barn doors fully open , you get about 2 feet of light surface. Just don't point the light up and let the tough-spun fall against the barn door screen. Tough-spun is not THAT tough after all.
To clip to the barn doors, you can use the venerable C-47, aka a wooden clothes pin with a metal spring, which can handle the heat and not transfer it to your fingers or gels, or all-metal "bulldog" or "binder clips", which will burn your fingers if handled hot without a glove. In a pinch, alligator clips or even paper clips can be used, but the point of the diffusion is to get it out ahead of the bulb a ways to make the point source bigger and thus softer, and also allow cooling air flow up the back side.
I was brought up using tough spun and I like it because it is so durable and heat resistant, being essentially spun glass cloth, lasts forever. It also doesn't rattle, crinkle, or make noise in wind. Other guys like to use tough frost or tough opal, or rolux: each gives a different quality of diffusion. You should go to the Rosco site or a local supplier and get one of their swatchbooks. They contain thumb-sized samples of every gel and etc. they make, with specs. The "tough" prefix refers to extra heat resistance, but note it does not mean heat-PROOF. Grab the swatchbook and a penlight flashlight. Shine the penlight thru the samples and see how they vary in their diffusion and transmission properties.
The minimum things I always have a sheet of in the kit for each light are tough spun and a square of black cinefoil, as well as color correcting gels for flourescent and daylight plus RGB primary color gels. The cinefoil can be used like barndoors, flags, or a snoot to control spill, or punch a few random holes thru it with a pencil and use it as a quick kookaloris, even in concert with a color gel. One of my fave techniques.
I have heard of home movie makers using plastic translucent shower curtains as DIY diffusion, but these will melt spectacularly if lit too close, they tend to cut the light output too much, and are a pain to hang. Plus the new plastic smell is funky:-) This is best used against a big window that's out of shot, or overhead in a butterfly frame I think.
If you have extra light stands, mic stands, or a flexible length of gooseneck with clamps on either end to clamp to the redheads' own stand, you could also bounce your redhead off a sheet of foam core or simple foil-covered cardboard as a reflector, makes a fine soft light indoors, though not very controllable. Crinkle up the foil into a ball before uncrinkling it and gluing it to the cardboard with elmers polyurethane glue or 3M 77 spray, to make micro sized breakup patterns in the surface like peening marks. This takes the harshest hot spots out of the reflector board. Should work great at about 45 degrees to one side and about 2 times the widest dimension of the board as a starting place. Then adjust to taste. A gold or bronze-colored reflector board looks awesome on non-caucasian skin types. Brings out the translucence of the outer layers of skin with an opalescent quality.
So you see, you can do a lot with a little, if you add some time, ingenuity and technique.
On the barn doors that I have (Ianero), there are little clips attached to one ( maybe two) of the doors. But, as Mark pointed out, they get a bit warm after an hour, so they are best used if you attach the diffusion before the light get too hot.
thanks guys, I guess I'm gonna have to experiment I'm gonna go and buy a bunch of different gels, frost, skin tone etc... all depends on the subjects too, so I guess it will be a onsite experiment. I always use gloves, got burnt too many times ;)