I've been tasked to manage lighting on a short zombie film.... We wish to bring out a natural cold, damp, Hazed autumn. We wish also to have light beams coming down from surrounding trees.
I was thinking ,maybe using a key light from the direction of the sunlight and using white screens to diffuse and soften the subject. For the light beams, install a light behind the tree. i wouldn't of thought its simple as that?
I think you will find it is not that simple. To get shafts of light you will need to first add “atmosphere” to the shot. That can be easily accomplished with some short of fogger (an old Mole “ramjet” fogger will eliminate having to run through the woods trailing an extension cord.) The hard part is a “hard” light source back lighting your scene several stops over your key in a wide establishing shot. On a budget there is really only one option and that is the Sun. This is one of those situations where scouting, choosing the right location, and planning your production day is worth more than all the grip trucks, tow generators, and large HMIs in the world, because nothing compares to the quality of that large plasma light in the sky.
In these situations, the approach that I find works best is to choose a location that puts the sun in the backlight position for the establishing master shot that is required to bring out the shafts of light and then wait until the optimum time to shoot that shot. Up to and after that point in time, shoot the close coverage under a full silk. Shooting the coverage under a silk offers a number of advantages. If the sun is in the wrong place for scene continuity, the silk takes the directionality out of the sun and knocks down its’ level by two and half stops. Now a smaller HMI light will have more of a modeling effect. Shooting into talents' down side under a silk, I find that a 4k Par through a diffusion frame is a sufficient key source for a medium two shot and it can easily be positioned where it needs to be to match the establishing wide shot when you eventually shoot it.
A good example of this approach is a scene I lit for a low budget feature that took place around a campfire in a small clearing surrounded by woods. Surrounded on all sides by woods, we knew that we would lose direct sunlight in the clearing early in the day and would need lights. We also knew that the scene was going to take all day to shoot because of its’ extensive dialogue, so we figured out where the sun was going to be throughout the day and where it would look best for our establishing wide shot. Where it was a two shot, mostly over the shoulder of one character talking to the second character who was standing with his back to the campfire with the woods behind him, we decided to wait until the sun had moved into a near back light position to shoot the establishing shot. So we shot our close coverage first with nothing more than a 4k Par and 1.2k Par under a 20x light soft frost on top of which we threw leaves. The 4k was heavily diffused and positioned so that it gave the talent the reverse key modeling that would be consistent with the wide shot but still attractive. The 1.2kw was used bare and was positioned as a backlight where the sun would be when we would eventually shoot the wide - this way there was always an edge in every shot for continuity.
When the time came to shoot the establishing shot, the shadow of the overhead frame and stands were thrown forward and did not interfere with the wider framing. Since we were still shooting under the silk, we were wider open on the iris and so our exposure dug into the dark woods and brought out more detail. The smoke from the campfire drifted into the woods, creating shafts of light where the sun broke through the tree canopy. What would have been a high contrast scene without lights, turned into a beautifully lit scene, and was accomplished without a lot of amps. The whole scene was lit with nothing more than a 4k and 1.2k Par and powered by nothing more than a 60A/120 circuit from a modified 7500W Honda EU6500is/Transformer Gen-set.
Guy Holt, Gaffer, Screenlight and Grip, Lighting rental and sales in Boston.