How to Deal with Artificial Illumination in Your DSLR Video
It is extremely difficult to shoot a DSLR movie after the sun goes down. That’s because artificial illumination plays by its own set of rules, which wouldn’t be so bad, except there’s so many different types, each with its own behavior. Gone is the predictability of sunlight and pro-active control of studio illumination. What’s not gone is your anxiety when it comes to figuring how to make the lighting work.
Unlike sunlight or your own lighting, street lamps are passive, and most can't produce a full spectrum of color. In other words, forget about completely removing that colorcast like you can with incandescent light.
Here are some bugaboos of artificial illumination:
Annoying colorcast: Not all light sources can produce a full spectrum of color. Depending on the lighting, the scene may render with a yellowish cast or cyan tint so that even a meticulous white balance will void the scene of color.
Harsh shadows: Sometimes they’re on the face; other times, they create too much contrast on the scene. When you adjust for them, the highlights get blown out. Fix the highlights, and the middle tones become shadowy and the shadows just black.
Unpredictable results: Sometimes you don’t notice the effect of color or contrast in the Live View window until it's too late. Get used to judging color and exposure in both the viewer and timeline.
Record night light, dark and bright
Artificial sweeteners, coloring, and flavors are examples of synthetic alternatives in our food supply. Their intent to replace natural ingredients with fake ones aims to reduce calories or imitate flavors, but in doing so, they sometimes cause side effects. Just read the package, and you’ll see the disclaimer. Well, artificial light isn’t much different.
When the sun hits the sack for the night, artificial lights come on duty for our benefit, you know, to prevent people from walking into walls or tripping over the curb. That's helpful to avoid stubbing a toe, but it doesn't do much for capturing a scene without a dominant colorcast.
On the bright side (pun intended), they provide intensity at a low cost. But on the other side of the street (pun intended again), they also have side effects. Tungsten illumination, although artificial, is not that different from natural light in that it produces light as a by-product of heat and still creates a full spectrum of color.
But tungsten is not very efficient, nor does it last that long before burning out, so it’s not a great long-term solution for illuminating wide-open spaces like Main street or a large parking lot. Forget about lighting a small stadium: The amount needed for the job would generate too much heat. These situations require a brighter, longer lasting, more efficient form of light known as a high intensity discharge lamp.
On a less epic level, fluorescent lights are another efficient light source. These long-tubed lights range from monochromatic to full-spectrum color and just about every variation between. Some are even used in studio lighting. There are so many different kinds. Next time you look at an office building, observe the varying colorcast from window to window. You’ll notice variations in color.
Film with shadows and highlights
The challenges associated with shooting a scene with a single light source include harsh illumination, deep shadows, and lens flare. You can work around these problems by either waiting for the sun to change position or by simply changing the angle from which you’re shooting the scene.
But imagine if you had more than one light to contend with. Well, that’s what you have with many night situations. With each light source doing its own thing, it can frustrate even the most patient of moviemakers.
Here are a few tips to take the edge off your nerves:
Limit your camera work. Tightly compose the shot to avoid light flaring into the lens and to reduce harsh shadows.
Use on-camera light. Although this small, harsh narrow circle of light is not usually flattering, sometimes it’s necessary to open a part of the scene or highlight a person in the scene.
Shoot day for night.