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Lighting Basics

Choosing the right light is first a matter of determining your specific technical and aesthetic requirements. Here are some basic types of photographic lights along with lighting techniques, some typical lighting setups, and specific suggestions for lighting a studio interview.

Types of Lights

A hard or intense light produces strong, dramatic highlights and shadows. It imitates the naturally bright light of a clear. sunny day. Fill light is typically used to soften these shadows and thus control contrast. Hard light provides easy, direct control of brightness and spill are fairly easy to control.

Studio lighting generally uses tungsten-halogen lamps ranging from 250 to 2,000 watts in intensity. These “quartz” lamps are more efficient than the common incandescent lamp, and do not darken with age.

WARNING: Quartz lamps get extremely hot, which makes ventilation important. Burns and even explosions are serious hazards when using these lamps. Replace lamps only after they are unplugged and cooled. Do not allow oil from fingers to be deposited on the outer glass (quartz) envelope of the lamp. This oily residue will concentrate heat and ruin the expensive bulb. Rough handling while the lamp is on can also damage the fragile tungsten element inside.

The normal utility electrical circuit has a maximum capacity of 15 or 20 amps at approximately 120 volts. One 500-watt lamp uses about 4.55 amps. A 650-watt lamp uses 5.10 amps, and a 1000-watt lamp uses 9.09 amps. To be safe, no circuit should be loaded to more than two thirds of its capacity to prevent overloads from power surges and to allow for possible weaknesses in the circuit. In other words, a maximum of two 500 or 650 watt lights should be used on a 15-amp circuit. Divide total wattage by 100 for a safe estimate of amperage. Use 12 AWG extension cords.

Hard Lights. A hard or intense light produces strong, dramatic highlights and shadows. It imitates the naturally bright light of a clear. sunny day. Fill light is typically used to soften these shadows and thus control contrast. Hard light provides easy, direct control of brightness and spill are fairly easy to control.

Focusing Hard Lights. Some hard lights have beams that can be continuously varied from flood to spot. This focusing ability gives the user control over the spread of the beam and the intensity of the light.

High Intensity Lights. Super spotlights direct hard light in a narrow beam over a long distance.

Wide Angle Lights. Broad-beam lights are semi-hard and non-focusing. They are used to light large areas evenly.

Soft Lights. Soft lights provide a relatively large, indirect light source, producing gentle, flattering highlights and shadows. They imitate the naturally diffused lighting of an overcast day. Such lower intensity lighting needs to be closer to the subject, and tends to spill, reducing contrast and thus requiring little or no fill light. Soft lights can be used as fill lights because they do not introduce hard shadows.

Light Adjustments

There are unlimited ways to alter lighting to achieve specific effects without have specialized lighting. Be creative. Bounce light off walls, ceilings, or other objects. Use various materials between the light source and the subject. For example, packing bubble wrap can soften lighting and produce some interesting effects. Here are some standard solutions to common light problems, ways to adjust the available light source.

Diffusion. You can diffuse and soften light even while using hard lights. Use indirect light (bounced off a neutral wall or ceiling), umbrellas, gels, scrims, or diffused or frosted glass. Soft light lamps alter the color temperature whereas scrims and neutral density gels reduce intensity without diffusing or softening.

Darkening. You can reduce brightness or intensity by flooding a focusing light, moving the light back, partially closing barndoors, using a full scrim, using a lower wattage lamp, or using neutral density gel. Black backdrops and walls absorb light, making light patterns more controllable.

Brightening. You can increase brightness by using maximum wattage, focusing toward the spot position. White (or other highly reflective) walls or ceilings will reflect more light and create a brighter, but less dramatic, effect.

Narrowing. You can control spill by using barndoors or snoots.

Lighting Accessories

Of the many accessories and attachments for studio lighting, here are the most common:

Barndoors. These metal flaps attach to all sizes of a light and allow considerable control over the precise pattern in which light falls on the subject. Lighting baffles are commonly called “barndoors.” Use of barn doors is most important on backlights, since these can cause objectionable lens flare if their light is allowed to strike the camera lens directly.

Flags. Various opaque materials can be used to block and sharply define the edges of the light source. They can simply be shaped from double or triple layers of aluminum foil and either clipped to stands or attached to the outer edges of barndoors. The further away they are from the light source, the sharper the light cutoff.

Gels. These filters all only a portion of the light’s spectrum to reach the subject. They primarily provide mood lighting, They also reduce intensity. Green gels work poorly on people but fine for backgrounds. Blue gels are particularly popular. Amber and red gels have lower transmission loss yet produce rich colors.

Umbrellas. These reflectors diffuse light and add tone or color.

Scrims. These special disks of screen wire soften lights and reduce their intensity slightly. Two or more scrims can be used in the same lamp to increase the effect. Half scrims or variable density scrims can be used for selective softening of lights. Scrims can also be used in lights that don’t already have protective covers or lenses to contain shards in case a bulb explodes.

Snoots. These “cans” attach to the front of lights. They narrow and focus the light.

Basic Lighting Setups

Generally, the rhetoric of lighting requires attention to four principles: clarity (enough light), credibility (realistic light), emphasis (focused light), and aesthetics (mood light). Most often the approach is to triangulate the light. First, the main or key (spot) light source focuses directly on the subject, typically from 45 degrees both horizontally and vertically. Second, the fill (flood or broad) light softens shadows and sets the level of light contrast for the scene. The backlight (kicker or hairlight) both illuminates the background and separates the subject from it.

High-Key Setup. Used to simulate daylight, this setup places the key light slightly above the subject and the backlight (100–150% of the intensity of the key light) above and behind the subject. The contrast ratio is set to 2:1 with a fill light half the intensity of the key light.

Low-Key Setup. Used to simulate nighttime, this setup places the key light slightly above the subject and the backlight (100–150% of the intensity of the key light) above and behind the subject. The contrast ratio is set to 7:1 with a fill light 15% of the intensity of the key light.

Front Setup. Used to simulate indoor scenes with overhead lighting, this setup places the key light high but directly in front of the subject and the backlight (100–150% of the intensity of the key light) above and behind the subject. The contrast ratio is set to 2:1 though a fill light may be unnecessary. The height of the key light controls the general illumination.

Side Setup. Used to simulate natural window light, this setup places the key light at eye level and perpendicular to the subject. The backlight (100–150% of the intensity of the key light) is placed above and behind the subject. The contrast ratio is set to 2:1 with a fill light half the intensity of the key light.


Lighting for Studio Interviews

To light a studio interview, you probably want to use flat light sources in front of your subject at about 45-degree angles. You might want to make one light stronger than the other by altering the distance from the subject. Use broad V-lights, perhaps reflected photo umbrella light for one of them. By bouncing your light into a white or silver umbrellas or directing it through a diffusion material, you can achieve “flat” or “soft” lighting. It gives anything with compound shaped surfaces and/or highly reflected surfaces (like a human face) softer, more natural shadows. Soft light wraps around the subject whereas direct light (spots) create glare spots on a curved surface (like a face), then drops off rapidly forming undesirable shadows.

Use a standard backlight above and behind the subject, which should create a rim of light around the interviewee’s head. This halo of spectral light should help the subject pop out from the background. Position the backlight carefully so that it’s stand does not interfere with the subject or walking paths.

You might succeed with only two lights at 45 degrees to the subject. A reflector board can soften shadows when using either one or two lights as in this one-light setup:

If you use reflected light, the wall or umbrella will absorb much of the light and may affect your camera exposure setting if not set to auto. For the Canon ZR40 DV video camera, you can’t set the f-stop directly, but you can choose the Portrait setting from camera mode and then press the AE Switch button on the camera body. Use the jog wheel to increase or decrease the aperture and watch the brightness change in the viewfinder. Use the VCR menu to set the data display to Camera Data and Date/Time. Then you can record a few frames and play them back, pressing the Data Display button during the process to see the f-stop setting. You can also use a light meter reading to compare recommended f-stop settings (and shutter speed). For portrait lighting, you want the background to be 2.5 f/stops brighter than the subject. Take a reflected light reading of the background (meter aperture open and pointed from the camera to the background). Then take an incident light reading of the subject (meter aperture closed and point subject to camera). With this method, the reflected reading takes into account the color of the background while the incident reading of the subject is independent of color and reflectivity. With the 2.5 f/stop difference, you can video the subject at correct exposure and render the background 2.5 f/stops brighter, evening out any background patterns or obliterating them entirely.