In the second of our Cinema Tools Pro-Tip series, Cinematographer Jim Ross shows you step by step how to set up a 12 by 12 overhead diffusion just like for a Hollywood movie or a professional TV commercial.
Transcript:
Today we're filming a commercial outside and to make sure our actors look good even in direct sun mixed with partial shade, we're employing a 12x12 overhead to diffuse the sun coming from directly above the actors.
Filming in harsh direct sun is one of the most common mistakes people make when filming outdoors. As you can see here in these earlier tips I recorded, the sun is unforgiving, giving harsh highlights and dark shadows which basically makes people look awful on camera. It didn't matter to me that I did not look cinematic here for a video blog, but for a commercial or film it matters a lot. Like for this expensive lawnmower - diffusing the sun makes all the close-up shots look much better.
First of all to utilize an overhead you need to have an experienced grip crew. This is not something you can do yourself. It takes at least two to assemble and mount an overhead and three or four is better.
The guys have connected four 12 foot speed rail sections with elbow speed rail joints that lock with allen hex wrenches. There are professional kits you can buy to assemble specific overhead sizes, but like many professionals I have a large compliment of speed rail so we build our own frame sizes as needed.
These heavy latches are called ears. These are how the frame is mounted onto an overhead stand, typically a hi hi, also known as an overhead stand. Be sure to mount the ears on the inside or the gobo handle on the stand won't clear the latch to tighten. Once the frame is assembIed it's time to mount it on the stands. You want a stand with a very wide base so it is difficult to turn over. Here you can see where the gobo handle is able to rotate to tighten. You mount the frame first - so when you attach the fabric- also called a rag - it won't touch the ground and pick up dirt or grass stains.
When you attach the rag start at the corners. Then work your way along each rail until you have all the sides nice and taunt. Use a standard bow knot - just like tying your shoe. This is because a bow knot releases on its own under stress and you want the knot to give if a strong wind comes along.
When raising the overhead you need to raise both sides at the same time. It's easier with two on each stand but not impossible for two strong guys or gals to manage it. Now moving an overhead is a tedious thing. When rolling lead with a leg. If you lead with the gap between two legs it can easily tip over. It's also best to lower the overhead as low as possible before moving it.
You will need plenty of sand bags to make the stands safe from tipping over. Even with lots of sandbags it is considered standard procedure to keep a grip stationed on each stand to babysit the overhead. So keep in mind when you add an overhead to your shoot you need to add two more people because to keep safe you need two people who have eyes and hands on the overhead at all times. This is even more necessary when using larger 20 x 20 overheads.
Overheads should not be used in windy conditions - they have enough area to act like a sail, turning your overhead into a gigantic kite. While that may sound funny this kite is no toy and is heavy and could tip over and seriously hurt someone.
Overheads are also excellent for use as bounce sources, bouncing the sunlight onto your talent or product. You can also use them to diffuse or bounce large HMI light sources.
When you use an overhead to diffuse the light you have now reduced the light on your actors or product. So you need to bring in side lighting to bring them up to exposure compared to your background. Side lighting, unlike top lighting, is beautiful. Here we position a 6x6 ultrabounce to reflect the sunlight toward our actors bringing the exposure back to where it should be. We also added a 4x4 floppy for negative fill to give a little contrast to our actors faces.
Ok, So why go through all this trouble? First to make actors look their best. In these shots from Into the Badlands diffused sunlight is soft and side lighting is flattering.
Second - no matter how long it takes to film a scene - the light looks the same. According to DP Shane Hurlbut it took several hours for him to shoot these scenes. If they did not have the overhead, as the sun crossed the sky the light would look different on the actors. As they cut to closeups the shadows of their noses would change. The light shining through leaves would be in different places. This way the shots match no matter if they did a wide angle at 11am and a closeup at 2pm. You want the same lighting consistency for your footage and with the overhead you will get that consistency.
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4 окт 2024
