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-   -   'Soft spill' versus 'hard directional'... (https://www.dvinfo.net/forum/photon-management/119950-soft-spill-versus-hard-directional.html)

Robert Davies April 21st, 2008 09:16 PM

'Soft spill' versus 'hard directional'...
 
Hi to all... this is my first post!

As a general rule it seems that whilst soft light produces nice graduated shaddows, it is hard to direct and tends to spill. Conversely, hard light is much easier to control but throws harsh shaddows.

I am curious to know what methods you guys employ to find a happy medium and create 'soft directional light'. How do you control the spill on soft light so that you can position it only in certain areas.

Always keen to learn a new trick!

John DeLuca April 21st, 2008 09:41 PM

Im interested in hearing how others achieve this too. My own method involves using crates and large barndoors on a softbox.

-John

Bill Davis April 21st, 2008 10:13 PM

This is precisely the purpose of a fabric grid.

Most pro softboxes have velcro affixed inside the lip of the fixture matched to velcro on the fabric grid.

The depth of the fabric louvers plus the spacing of the squares limits the light dispersion.

Result - soft yet reasonably directional.

Dan Brockett April 21st, 2008 10:50 PM

Can't work without my eggcrates. I have four Chimeras and four egg crates. Man, those suckers are expensive but gotta have them. Sometimes use a piece of Duvetine or a solid as well, depends on how much room I have to separate the key from the BG.

Dan

Josh Bass April 21st, 2008 11:38 PM

May I assume you are operating on a limited/low budget? Unfortunately, while soft light is beautiful, it is difficult to control without the right tools, which can often mean big bucks.

Eggcrates are neat (I wish I had one for my chimera) but, they only take you so far.

To get real control, you need something large and opaque to block the light from a softbox or other soft source, off the areas you don't want it. We usually call these "flags", and there are "real" ones made of duvetyne (sp?) that have a metal frame, meant to be used with a c-stand and grip head. You can make your own with anything like cardboard, black foamcore, etc. You want something dark 'cause the idea is to keep the light off certain areas, not bounce it around even further. Anyway, a 2x3 sized surface is a good place to start. 4x4's even better, if it fits in your vehicle. You could get an 4x8 piece of foamcore, slit it so it folds, and be able to fold into 2 4 foot piece for transport, then you'd have a huge 4x8 flag. These can be affixed to a light stand with a spring clamp (movie lingo is "grip clip"). Foamcore and cardboard, etc. is the low budget way to approach this. If you have the cash, invest in C-stands and real flags meant to be used with said C-stands.

A common application for this kind of thing is a talking head interview. You normally have to flag light from the key light, usually a soft source like a chimera/softbox, off the background, because it washes out your background light and takes away contrast from the background in doing so. So you bring a flag in, 2x3 feet usually does it, and position it in such a way that it cuts off most of the light hitting the background without cutting the light off the subject. Hard to describe in more detail without pictures.

A rule is that the farther your flag is from a soft source, the more defined/distinct the "cut" is (the shadow of the flag), but the less effective the flag, because it's not blocking as much light. The closer to the soft source, the softer the cut, and the more light it blocks. So if you had a soft source, and wanted a hard cut on the background, and you can see a lot of background (wide shot), you'd probably need a very large flag. Of course, soft light naturally falls off much quicker than hard light because it's less focused, so if your soft light is very far from your background, may not be an issue.

John DeLuca April 22nd, 2008 12:31 AM

1 Attachment(s)
Eggcrates are neat (I wish I had one for my chimera) but, they only take you so far.

Hard to describe in more detail without pictures.
QUOTE]

Check this out. Its a pic from a recent interview I did for the Stephen A Comunale jr family cancer foundation. We are still setting up the lighting, but you can see the chimera brand flags at the end of the softbox. The K5600 Jokers (200/400w) looked gorgeous with the warm accent lighting in the ballroom.


-John

Josh Bass April 22nd, 2008 03:15 AM

What you're calling "flags" in that pic, I would call something else (not saying I'm RIGHT, but my brain thinks of those as barn doors or something).

To the OP-

The kind of flag I mean would go on a separate stand, in front of one of those softlights, just a short distance (maybe not even a foot) away for this kind of thing. Some people bring it in from the side, some people bring it in from the top. You sort of move it in and out, trying to find that perfect balance between cutting the light off the wall that's behind the subject, and cutting too much light off the subject themselves. And of course, keeping the flag out of the shot.

Robert Davies April 22nd, 2008 03:18 AM

The egg crate is indeed a wonderful thing... I have a 40 degree crate for my Chimera and I love it!

We have a bunch of Kinos at work which aren't bad either, although I don't find those quite as soft as a softbox. These Kinos are fitted with barn doors and in reference to Josh's comment regarding flags, I do find these too close to the source for effective cutting.

I have a couple of Westcott collapsible flags (for easy transport) which fit a heavy black cloth. These are pretty handy but something larger would be a great addition. I've never thought to make a 'concertina' flag from foamcore... that's a great idea!

Another handy trick I find for reducing spill on backgrounds it to bring your key light nice and close (this will not be appropriate for all situations but certainly helps for talking heads). This should create a nice exposure contrast from your subject to your background (inverse square law).

Thanks for the input guys... your knowledge is much appreciated!

Josh Bass April 22nd, 2008 03:40 AM

Yes!

I'm always wondering why DPs put chimeras as far away from their subjects as they do for talking head stuff. I love that super soft light, and if you put the thing 8 feet away, it's not gonna be super soft unless it's pretty large.

I guess it's a comfort/heat thing, or an exposure thing, or a "maybe they don't need it to be super soft" thing).


I PA'd on a low budget music video once where the DP set up a key light that was something (2K? 5K?) going through a 4x piece of diffusion on a stand, and he positioned four 4x flags, around said diffusion, one at the top, one at the bottom, one at each side, giant barn doors in effect, to get a very contained, but also super soft (subject was only a few feet away) source.

Kinos are neat. They take up little wattage, are cool to the touch, and already pretty soft by nature. So you can put 'em right up near someone and they shouldn't feel overheated. Most DPs that I've seen, when they use Kinos to key, will diffuse them, using 216, gridcloth etc. Or they'll use one of the larger fixtures, instead of the 4x4 kinos, or 2x4 kinos, like that flathead 80 thing. You can set up two kinos very close together, parallel to each other, and put a 4x piece of diffusion in front of them, for a nice soft source.

For those who can't afford lights that are 800 bucks a piece, a cool soft light (I haven't done this yet, but have heard DPs rave) is called a "booklight". What you do here is take something like foamcore, an 4x8 piece, and fold it in half so you have two 4x pieces. You set this up in a V shape, with the open part of the V toward your subject. Across the opening in the V, you stretch/position some kind of diffusing material. So now you have a closed triangle. You take a light , and put it inside the triangle, pointing it toward the crease in the V (AWAY from the diffusion). Your original light source is now bounced off the foamcore and then further diffused by the diffusion material, for super softness. You need quite a few stands and a pretty powerful light (all that bouncing/diffusing kills the final output) for this to work.

I've also seen a simpler (well, not really) setup where you take a powerful light, like a 5K, and put it through a 4x piece of diffusion on a stand in front of it, and then a few feet away, ANOTHER piece of 4x diffusion on a stand. I can't remember exactly how this works, but one of those pieces of diffusion has to be significantly softer than the other, or it just cuts light out instead of further softening it. I think the diffusion closer to the subject needs to be softer. Could be wrong.

Oh, and a thing to be wary about with regards to those eggcrates is that they can cut a LOT of light out, depending on the strength of the eggcrate. They also appear to warm up the color temperature of the light.

John DeLuca April 22nd, 2008 04:01 AM

I guess technically they are barn doors (without the ability to focus like real barn doors). They give you a bit more control when a crate is not enough.

-John


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