What sized backlight for Interview

[Bryan Aycock]

I recently shot an interview, and had an Arri 650w fresnel as a key, a 300w for a fill, and a 150w for a backlight. When I exposed for the shot, I realized that the little 150w could not throw enough light on his head and shoulders to see a differnce with the 650 & 300 burning in the front. Is it a general rule to have a backlight just as powerful as my key, b/c I fell like that would have made a difference in separating him from the background.

[Richard Alvarez]

Light falls off at the inverse square of the distance... SO

A less powerfull light (in wattage) will need to be closer to the subject in order to appear brighter.

It's possible you could have made your 150 watt back light work, IF you could have placed it in a position where it could throw enough light. ALSO where it hits your subject can make a difference. Hairlight will 'halo' the hair, shoulder light can put just a hint of edge on a dark suit, but will be lost on a lighter one. (Of course, spotting in on the light will also throw a sharper edge.) A backlight will show up better if the subject is against a dark background or 'limbo'.

[Dan Brockett]

Richard hit the nail on the head, good advice.

Were you using hard light or a softbox on your key? An Arri 650 puts out a lot of light, I usually scrim down with at least a single when keying with it puched through a small Chimera. I typically use an Arri 650 as a key through a small Chimera, a white or gold flexfill as a fill source and an Arri 150 fresnel as a hairlight or rimlight. Sounds to me like your ratios were off which would make sense. Unless you needed a super wide framing, the Arri 300 sounds like overkill as a fill light, I would have reversed and used the 150 as a fill and the 300 as hairlight.

But I do succesfully use the Arri 150 fresnel on a dimmer as my typical hair/rim light when keying with the Arri 650 fresnel.

You should set up the old camera and monitor and shoot tests and you will soon discover the correct lighting ratios.

Best,

Dan

[Loren Miller]

According to Doug Jensen's excellent how to DVD on interview lighting, a 250 watt Lowell Pro light, barndoored, does the trick. His Vortex Media should be a sponsor here. He delivers a nicely distilled mini-workshop just on lighting interviews that I found helpful. Recommends a kit costing less than 1500.00-- and itemizes it line by line, dollar by dollar.

www.vortexmedia.com

I own no stock in Vortex Media. (But i wish I did.)

- Loren

[Joe Barker]

Get someone with a large flecki to bounce the light and fill in the gaps.Cut down on the wattage,nothing looks more phony than a blown out interveiw scene.

[Sal C. Martin]

I have a rifa-lite 66 (750w). Would this be too powerful and "blow away" my interview subjects? I plan toplace it farther back and somewhat off to the side for my interviews.

[Seth Bloombaum]

Originally Posted by Sal C. Martin

I have a rifa-lite 66 (750w). Would this be too powerful and "blow away" my interview subjects? I plan toplace it farther back and somewhat off to the side for my interviews.

Sal, test it out.

I think the rifa-66 is a very nice light, and capable of supporting a two-person interview. You'd need to get it far enough away to light two people evenly.

The rifa series are very efficient, so, yes, a 750 puts out a lot of light.

Be aware that if in your tests you find you're working the rifa so far away that it's inconvenient, or you're starting to lose the "wrapping" effect of the soft box, you can lamp it with a 500w bulb. http://lowel.com/rifa/rifa66_b.html#info

[Glenn Chan]

You could also place diffusion on the light (i.e. use clothespins to hold the gel) to knock down the intensity... in case you usually want the 750W bulb in there. In this case, you just use the diffusion to do the same thing a neutral density gel would do.

[Tom Tanquary]

Originally Posted by Sal C. Martin

I have a rifa-lite 66 (750w). Would this be too powerful and "blow away" my interview subjects?

"blow away" is usually a function of bad exposure and not getting the ratios of key-fill-back-background levels right.

Using a 750w, even in a Rifa, is a lot of light. I'm always in a bid to save power and heat so I try not to use anything over 500w. But if you do a lot of diffusion in front of the lights (like the movie crews that start with a 10K and reduce it to 25fc with layers of silks) then more wattage is required.

As for backlights, I'm using that small 250w Rifa on a dimmer and I find that works great. Sometimes I just bounce a 100w into an art card for a back. You find that just like the key light, a softer back light can make a world of difference. If you've ever had a female subject with "the frizzies" a hard back light can drive you mad. A soft back light reduces that problem to almost unnoticeable while still getting a great hair light with separation.

t

[Guy Cochran]

Toss an Egg Crate on that Rifa 750 and you'll cut the output of the light and have more control of where the light is going.