Lighting for a film shot at night in a forest
Posted 27 December 2008 - 05:29 AM
The Director is still sorting out different options he has with respect to the exact lens he'll be able to get for the film, and he's still working on the storyboard, so for now I can't list any specifications with respect to those two things and I can't start on a detailed lighting design just yet. For now then I'm just trying to get some preliminary information on what general lighting equipment works best in night exterior shooting like this and what tricks and setups can be most effective given some of the limitations in play.
It's important to note that when I was hired I immediately thought about shooting parts of the film between 4pm and 6pm with a subtle day for night (the sun goes down here this time of year at 6pm), but I was told the location we're using is a large county park, and the county only grants permits for night shooting, meaning that the convenience of a day for night for some scenes will not be possible. It's also important to note that I will of course have a generator to power all of the lights. For now, Here's what I have planned:
- I've chosen to shoot the film in 4K RAW using the REDCODE codec (the file size created by the 27 MB per second is huge, but still manageable for us).
- My preliminary lighting setup is obviously geared toward low key lighting, with several 5K HMI's serving as key lights, illuminating the forest as a whole. Most of them will be rigged at only about 20 feet off the ground, because the budget doesn't allow for higher stands or cranes. I plan to have them on an uneven line, and where each light is placed will depend on how much vegetation is blocking its beam. The lights closest to the actors will be 1/3 diffused and all of the lights rigged at 20 feet (which will be about 2/3 of all the lights) will be aimed diagonally, to shine down on the actors' bodies, while the other 1/3 will be rigged and aimed at body level. Additionally, I plan to add several 1/3 diffused 1K HMI's near the actors for fill and back light on closeups and medium shots.
- The reason I'm interested in using HMI's is because of how they give more output per watt of electricity consumed (giving me as much light as possible in the dark) and because I plan to set the camera's white balance to 3200K, which would make the image bluish due to the 5600K color temperature of the HMI's, allowing me to simulate moonlight without having to use color correction gels or worry about changing the gels from time to time, something that at the height at which these lights are going to be placed, and with the small crew we're having, is inconvenient. If the image is too blue, I can always warm it up with the camera's manual color temperature controls.
So I'd just like to know if it seems to you guys that I'm on the right track with respect to some of the preliminary ideas I have, and if anyone has any additional advice for shooting large night exteriors, shooting them with a RED one, or doing both while under a small budget. Thanks a lot guys.
Posted 27 December 2008 - 11:51 AM
You may want some weak soft light to add to your hard streaks of moonlight (HMI's don't come in 5K and 1K, by the way... either 4K or 6K, and either 575w or 1.2K are the closest choices.)
I've done some soft overhead fill by either stringing Chinese Lanterns with blue photofloods or daylight CFL's, or with single Kinoflos with diffusion on the doors, mounted high on trees. Or if I had a larger clearing, an HMI lighting balloon, though those are usually too bright for fill, more for a soft key.
Posted 27 December 2008 - 03:01 PM
Posted 26 January 2009 - 12:06 PM
Hey Everyone. I just signed on yesterday as a DP for a short film to be shot in February on the RED one here in Miami, FL. Almost the entire film takes place in a forest at night, and since I haven't worked with the RED one or in a forest at night, I'm curious to know if anyone on here can help me out with some questions I have about lighting setups for large night exteriors and things like that. ….. It's also important to note that I will of course have a generator to power all of the lights.
HMI's for moonlight makes sense for the RED since it has a native 5000K balance, so it's better to shoot under daylight and add some slight blue in post by picking an inbetween color temp balance, like 4200K or something, for a half-blue look.
David is right that it would be better to use 5500K light sources since the Red’s native color balance is 5000K. But this requires a different approach to lighting the scene than is traditional. In the past, it was customary to use 3200K light sources for night shooting because most high speed films and video imaging systems were balanced for 3200K. With this traditional approach HMIs were used to create blue moonlight and tungsten lights were used to create white or slightly warm lamp-light. In this approach CTO gels are used to either make the HMIs less blue or the tungsten warmer.
Using tungsten light sources for a night scene when the Red’s native color balance is 5000K doesn’t make a lot of sense. Balancing tungsten to 5000K is not very efficient because full CTB cuts the output of the light by 70% in converting it to 5000K. A 1000W 3200K light becomes a 300W 5000K light when you put Full CTB on it. A 400 W HMI will give you considerably more lumens/watt than a color corrected Tungsten 1k, and use up a lot less power available from your generator.
It makes more sense to use HMIs to light for the Red’s native color balance of 5000K because they provide more lumen/watt and require less filtration with gels. In this approach raw HMI light would provide white light, Half CTB gel would provide moonlight, and Qtr. CTO gel would provide warm lamp light. I personally believe you should always combine color temperatures in a frame. You can shift your overall color balance to the cool side in the camera or in post to create moonlight, but without a white light or warm light reference in the frame, your audience will subconsciously adjust and filter out your moonlight effect. Putting white light in the frame gives your audience a reference point and they will not filter out a color effect like moonlight.
One of the downsides to lighting for the Red’s native color balance of 5000K is that it requires an all 5000k balanced lighting package and HMIs are considerably more expensive to buy or rent. A cost effective alternative to HMIs are Kino Flo florescent light fixtures because they can use either 3200K or 5500K tubes. When using 5500K tubes to light for the Red’s 5000K native color balance, you can warm the lights without losing output to CTO gels by simply mixing in 3200K tubes with the 5500k tubes. The drawback to using florescent light fixtures to light night scenes is that they generally have a very broad soft light output that drops off rapidly which means the units need to be positioned close to the subject they are lighting. This characteristic makes them better suited to lighting documentary interviews than dramatic night scenes. The one exception to that rule are the Kino Flo ParaBeam fixtures.
The Kino Flo ParaBeam fixtures use computer aided designed (CAD) parabolic reflectors that focus the light output at about 16 feet (5 meters). This feature makes the Kino Flo ParaBeams well suited for HD Digital Cinema, because it doubles the light output of the lamps where it is needed most for lighting dramatic scenes - at a medium distance. Compared to the Kino Flo Diva-Lite, which uses the same four 55 Watt compact lamps and the same ballast, the ParaBeam 400 is twice as bright at 12' – making them a suitable key source for lighting dramatic scenes. Kino Flo also makes available for the ParaBeam fixtures a number of innovative accessories that enhance their production capabilities for HD Digital Cinema. Accessories include barndoors, a gel frame, a diffusion panel, and Honeycomb Louvers. Honeycomb Louvers are available in 90, 60 and 45 degrees and provides beam control similar to that of swapping lenses on an HMI Par.
So that you can power more lights off your generator, I would recommend a lighting package that consists of HMI Pars to light your deep background, Kino Flo Parabeams to key your talent, and a traditional Kino Flo 4’ bank to fill. Though it will be harder to find in smaller heads at your local rental house, I would also recommend using HMI electronic ballasts with Power Factor Correction (PFC.) Formerly only available in the higher wattages, this advanced electronics reduces current spikes and harmonics in the power line and contributes to a more economical use of power. 800 & 1200 Watt ballasts with PFC use considerably less power than conventional electronic ballasts. A brand name to ask for is Power to Light (P2L). because P2L is the only manufacturer I know of that is incorporating Power Factor Correction (PFC) into 800w, 1200w, and 2.5kw/4kw ballasts as a standard feature. Where PFC Electronic ballasts require less power to operate HMI lights, they enable you to operate not only more smaller HMI lights off of location power outlets, but also larger HMIs lights off of location power outlets than was possible before. For example, PFC enables P2L’s 4/2.5kw LVI ballast to run 4kw HMI lights off of standard wall outlets with the appropriate adapter.
In the interest of full disclosure, I should say that in addition to being a gaffer, I also own and operate a rental house that rents and sells a lot of the equipment recommended above. If it sounds like I’m hyping the P2L line it is not because we rent and sell them. We are also dealers and rental agents for Mole, Power Gems, and ARRI. As a professional Gaffer of a lot of tight budgeted historical documentaries for PBS’ American Experience and The History Channel (see my “credit-entials” on Imbd), I think these ballasts are a major development worth noting.
While not a tremendous advantage when plugging into house power, the power efficiency of PFC ballasts can make a huge difference when powering a lighting package off of portable generators. For example, where a Kino Flo Parabeam 400 draws only 2 amps, the 8 Amp difference between using a P2L PFC 1200W electronic ballast and standard non-PFC 1200W electronic ballasts, can mean the difference between running four additional Parabeam 400s on your portable generator or not – I think you would have to agree that is a major boost in production capability. And when you start to add up the incremental savings in power over multiple HMI ballasts in a lighting package, add to it the energy efficiency of light sources like LEDs and Kino Flos, and combine it with new distribution technology we have developed that provides 7500W of power in a single 120V circuit from a modified Honda EU6500is portable generator, you have what, I would argue, amounts to a paradigm shift in how to approach lighting night scenes.
For example, on a recent independent short I used our modified Honda EU6500is Generator to power a lighting package that consisted of a 2.5kw, 1200, & 800 HMI Pars (with PFC ballasts), a couple of Kino Flo Parabeam 400s, a couple of Parabeam 200s, and a Flat Head 80. Given the light sensitivity of the Red Camera, this was all the light we needed to light a large night exterior. The scene takes place behind a mall, rather than the woods, but the principles are the same: we used the 2.5 HMI par to light the deep background, the 1200 HMI par to light the near background, and the 800 Joker was mounted on a Source 4 Leko with a bug-a-beam adapter to create a window pattern on the ground from a building that doesn’t exist but you don’t see that in the movie. We used two Parabeam 400s to key the talent and a Kino Flo Flathead 80 to fill the entire scene.
We pitched the color temperature of the lights to the Red’s native 5000K color balance as follows: the 2.5 & 1200 Pars were gelled with ½ CTB for moonlight. We put half CTO on the Joker 800 to create warm window light. We mixed 3200K tubes into the Parabeam 400 on the “window” side to create a warm key source motivated by the window. The Parabeam on the other side was gelled with ¼ CTB to create a cool key source motivated by the moonlight. Finally, we lamped the Flathead 80 with only 5500K tubes to create a slightly cool fill. To see the final results, use this link - www.screenlightandgrip.com/html/hdfilmstrip4lg.html - to our website where we have posted more detailed information on the lighting package we used along with production stills from the movie.
Guy Holt, Gaffer, ScreenLight & Grip
Posted 26 January 2009 - 01:25 PM