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Old July 30th, 2010, 06:16 PM   #1
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creating contrast with light

I am wondering how to create between 6:1 to 10:1 contrast ratio with 4000 watts of light, umbrellas, softboxes, and home depot clamp lights. Here are a few variables...

1. shooting with a GH1 with a canon 16 to 35mm 2.8L zoom on an adapter that doesn't allow me to control aperture. I know this is not ideal, but I need the wide angle and haven't found an FD option yet. I also have no Nikon options nor an adapter that makes it feasible.

2. have other lens options but want to keep the lens as open as I can to selectively focus. the lights can dim but that changes the color temp and creates a mismatch between other light sources and practicals.

3. the space is incredibly cramped. very tight shooting and absolutely cannot be helped or changed under any circumstances.

4. there is a lot of physical action that also cannot be helped or changed under any circumstance.

5. we have to accentuate the artwork on the walls, and the decor around, but also have to emphasize the characters and highly stylize the scene.

This is beyond my innate ability at this point, and I don't have hours to figure it out on set. There is no budget to hire somebody, no opportunity to ask for help, and nobody available to help the weekend of the shoot. There is no diagram because the room is small and we have a table and a couple of walls with artwork.

Any suggestions?
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Old July 31st, 2010, 03:48 AM   #2
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The contrast ratio has nothing to do with amount of lighting power you have available, it's ratio between the key and the fill or the shadows.

For higher contrast lighting In a confined space you need to the prevent the light from bouncing off walls etc and adding fill to your shadow areas. This is commonly done be controlling the light by the use of black flags, unfortunately, the softer the light source (larger area) the larger these flags need to be. You may even need to use black drapes. Hard light like a Fresnel spot is much easier to control under these circumstances, but you may prefer a softer light.

You may find that a bounce fill will be more than enough for higher contrast lighting. This may not even require a dedicated light, bouncing some of your key light as fill may be enough.

To reduce your light levels you can (a) use a lower wattage light (b) use scrim - sort of metal net mounted in front of the light (c) use neutral density lighting gels.
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Old July 31st, 2010, 04:18 AM   #3
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Usually, when I hear people saying they want strong contrast ratios, what they REALLY want is strong shadows. There are a number of ways to get strong shadows. I'll offer a few guidelines and a few comments.

First, getting strong shadows in a small space is always quite difficult. Unless the walls are VERY dark. If the room is white, paint it.

Second, the previous poster indicates that the power of the lights you have is not pertinent to the contrast ratio. While I understand the comment, I disagree to a point and I'll explain later.

This almost sounds like a scenario to repaint in post with just getting a hint of what you want in camera. You have have a lot going against you right now.

Ok that said, here are some things.

1. Toss out any bounce, umbrella or softbox you have. If you want strong contrast, these things are not your friends.

2. Reduce the number of sources of light on the set. Try to work with 1 or 2 lights. The more lights you have, the more they will even out the exposure. That is unless they are coming from the same direction.

3. Flag like crazy. You need to keep light off the walls and ceiling.

4. Powerful lights further from the talent will create harsher shadows than less powerful lights near the talent.

5. Try to light your actors from the 10 and 2 positions. This means the light is pointed to the back of their ears in a straight line. Less light is going to creep around them this way.

If you can offer a diagram of the room, and show where the actors will be, where the practical lamps are, and the blocking, I'd be happy to mark up light positions for you.
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Old July 31st, 2010, 06:14 AM   #4
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Yes, a greater light distance will give your shadows a harder edge. Another characteristic, but perhaps best separated as an element from the contrast ratio. For example, you can have high key lighting (low contrast) with a hard shadow edge, not often seen these days, but seen in older films and TV.
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Old July 31st, 2010, 11:25 AM   #5
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Good point Brian. But given the size of the room, getting a softer shadow transfer without spilling all over the place is going to be near impossible. Additionally, it sounds as if the actors are going to be moving around in this small space quite a bit, so you're not really going to be able to get in close with a big source and at a good angle.

Of course, a diagram of the space would go a LONG way to having some idea of what's happening. We don't even know if there is a window in this room or any practicals.
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Old July 31st, 2010, 12:05 PM   #6
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I'll touch on a different part of your original post as the lighting is being handled by much more experienced folks than I ;)

You do have exposure control over your lens, just not aperture control... you can always ad ND filters to knock down the amount of light coming in, allowing you to overlight the key side a bit to increase your contrast ratios.
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Old July 31st, 2010, 12:52 PM   #7
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In practise using hard light may be the only option, controlling soft light would be more difficult. Much really depends on the action and perhaps the key soft light is a practical or even something like the light reflecting from say a book into the actor's face. There are a number of choices that could be made either way depending on the scene.
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Old July 31st, 2010, 02:46 PM   #8
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In close ups, you just need a grip just off camera with a big sheet of black foam core to block light on the fill side ;)
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Old August 7th, 2010, 10:29 AM   #9
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Sorry, Ive been out of the country... I'll try to post something like a diagram when I get back to the states... but everything posted has been a big help. I'll give more info in a couple of days.

Thanks
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Old August 8th, 2010, 08:16 AM   #10
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Study the film noir genre. Lots of great examples there and much of it was done with very low tech simple setups. The look of those films was more about the use of light & shadow than anything else and were often done on very small budgets.
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