Making day resemble night on your screen means tinting the overall images blue, then adding white light, and adjusting contrtast and brightness to sell the trick.
Shooting "day-for-night," of course, means recording night scenes in daylight. It's done all the time because casts and crews tend to be less grumpy in the afternoon than at midnight and because lighting a large night exterior takes a truck full of lights, a honking-big generator and more bucks than you have for your whole show. In the halcyon days of black and white movies, day-for-night was easy because a red filter on the lens pumped up the contrast and recorded blue skies as jet black. Under-expose half a stop and you were in business. It's a bit trickier in color, but still simple enough so that you can create very convincing night effects.
But do you want to? Camcorders have ample sensitivity for shooting at night on urban streets and the real-world lights visible in the shots deliver an atmosphere you can't duplicate without them. So, if you have enough ambient light to shoot night-for-night (and you want the authentically grainy look of increased video gain) you may want to cajole your cast and crew into staying up late. Otherwise, read on.
The Basic Recipe: Exteriors
Successful day-for-night shooting depends on the purely conventional notion that night light is bluer than daylight (it ain't necessarily so). As you probably know, videotaping outdoors with the camcorder white balance set to indoors turns everything blue, so the first step is to do just that.
To make the trick convincing, you have to sell the gag, that is, supply extra evidence that the illusion is actually reality. So the next step is to add moonlight. In normal outdoor shooting, you'd make the sun your key light, then add fill and back light with reflectors. But in shooting day-for-night, you do the exact opposite: instead of making the sun your key light, use it exclusively for rim lighting by positioning performers with the sun behind them. This will dust their shoulders with light and throw their faces into shadow (Figure 1).
To make those faces visible, use reflectors as key and fill lights. Balance your lights so that the backlight (the sun) is brightest, the key light is hot enough to show facial details, and the fill light is faint (or even omitted) to leave deep shadows on the fill side. Don't let the shot become too contrasty, however. It's better to get a good, balanced image on tape and then play with the contrast in postproduction.
Place those reflectors low, perhaps even below eye level, so that the light rakes across the performers instead of falling down on them. Although these reflectors presumably represent actual lights, convention allows them to share the overall bluish cast of the moonlight. Next time you watch a Hollywood night scene, just try to figure out where the heck all that reflected moonlight is coming from.
Finally, try to get some incandescent light into your frame and, if possible, on your performers. It might be light through a building window, a streetlight, car headlights or maybe a flashlight (Figure 3). On the indoor white balance setting, these lights will take their proper white color, thereby supporting the idea that the bluer outdoor light is moonlight.
To throw light out of a window, place a light behind it and to one side, so that it shines through the glass. Because the daylight outside is so strong, you may need to gang several halogen lights to make the window brighter than the exterior. Try to block the action so that it moves in and out of these white light accents. For close-ups, you can place off-screen lights near enough to read strongly (but watch out for heat on the actors).
One more thing: be sure to frame away from the sky, because the light color will give you away every time. Old spaghetti westerns are famous for their fake day-for-night shots. If you must have a wide shot that includes sky, shoot it on a cloudless, blue-sky day, use a polarizing filter to darken the sky as much as possible, and plan to keep the shot very short so that viewers can't really study it. Dial some under exposure in post and you can probably get away with it.
So far, we've depended on direct sunlight for a full-moon look, but what if you have to shoot in the shade or on an overcast day? The answer is to tape anyway, using the reflectors and incandescent lights as we've suggested. Deploy hard aluminum reflectors close to the performers. The indirect light will be hot enough to make them effective, but not enough to deliver their usual painful glare. The result will look perfectly convincing after you've tweaked it in post, as explained in the sidebar.
You've seen it in a hundred shows: the character puts down her book, pulls up the covers and turns off the bed lamp, leaving only the soft light through the window to reveal the thoughts chasing across her eloquent face. Camcorders are sensitive enough to work in actual room light, so why not light it realistically: put a screw-base halogen in the practical bed lamp, get your exposure setting and lock it off.
Right, and have your frame go black when the bed lamp turns off because the ambient room light is four stops lower. But we still want to see in this room, so we'll reduce the illumination and then sell it as moonlight.
Once again, set white balance so that the halogen bed lamp reads as white. Since you may not have a source of daylight, cover the lamps of one or more soft lights with blue gels and use them for ambient lighting. Place the lamps to hit the off-camera side of the subject's face (they'll wrap around enough to provide some fill) and about 15 degrees above eye level. Watch your monitor as you move them backward and forward until you can see detail in the subject's face but the overall image is dark.
If you have burglars breaking into a museum, they'll have flashlights. Light the overall scene with blue-gelled halogens and establish those flashlights on screen. For close-ups, use a small spotlight (preferably the type with a lens) to stand in for the flashlight.
Whatever the dramatic situation, the basic lighting concept is the same: set white balance for incandescent, light with blue-gelled instruments and have some halogen light (and light sources, if practical) in the frame for reference.
We've already mentioned lit windows and flashlights, but there are as many other practicals (light sources you can see in the shot) as your ingenuity can supply.
Streetlights are great for atmosphere. To simulate the effect, aim a spotlight almost straight down on your subjects, then fill just enough with blue-gelled light to prevent black eye sockets and Hitler-moustache nose shadows.
Car headlights can be treated like flashlights: establish the light source with real headlights, then light closer shots with key lights placed about three feet off the deck so they aim slightly upward. In many cases, actual car lights are bright enough to function as movie lights, but don't use the yucky bluish types found on some boyz import cars. The whole idea is to contrast the blue ambience with headlights of honest white.
Room practicals can be hard to balance because you can't move them closer or further away, at least not when they're in the shot. Dimmers work well, down to maybe 75-percent of full power. After that, the light is too yellow to look real.
Of course, you do want that yellow/orange look for firelight. To achieve that, follow a slightly different plan:
- Use a straight halogen lamp to set the white balance (preferably by bouncing its light off a white card and into the lens).
- Gel the ambient light lamps blue, as usual.
- Either run the incandescent firelight down on dimmer or gel it orange. I prefer the dimmer because you can make the fire flicker by wiggling the control.
- Add a "hula skirt" of newspaper strips attached to a horizontal stick and waved in front of the light and you've got warm firelight on your subjects with cool blue shadows behind them.
Contributing Editor Jim Stinson is the author of the book, Video Communication and Production.
[Sidebar: Day-for Night in Post]
Night scenes are generally darker and have more contrast than usual and this effect is easy to enhance with your editing software. Don't work on individual shots, but on fully edited night scenes. When you've edited a day-for-night sequence:
- Darken it until it looks more like night.
- Increase the contrast until shadows and dark areas start to lose detail.
- Re-adjust the brightness and contrast until you like the effect.
You can also adjust the overall color cast, especially if you don't have halogen lights adding white light to the scene.
Finally, if you must have a wide shot with sky, try selective color replacement. First, temporarily remove the overall blue cast, and then replace the blue of the sky with black. Finally, re-tint the sequence so that halogen lights are white and the rest has a bluish cast. This can work if you have sharp boundaries between the sky and everything else, but will be very difficult to pull off with fuzzy boundaries, such as the sky seen through trees.