Module 36

Updated: 08/04/2005

Lighting:
Some
Final Issues

Before we close the topic of lighting, there are still a few important issues that need to be covered.

Video cameras used to be inferior to film stocks in their ability to handle brightness ranges. This gave film a definite advantage.

Today's CCD/CMOS cameras have not only caught up with the brightness range capability and general look of film, but the best video cameras can handle brightness ranges beyond those of typical film stocks.

Not long ago lighting directors had to approach lighting for film in a different way than lighting for video. Not anymore. George Spiro Dibie is an award-winning Hollywood lighting director (six Emmy awards and 11 nominations) with many years of experience lighting for film and TV.  Dibie says, because of today's CCD cameras, he can now "...light for my video cameras exactly the way I light for film cameras."
 

Following Source

Dibie also emphasizes a concept we introduced earlier: following source.  "Windows, doors, lamps...these are the sources of light in a scene. [For]...one camera or multiple cameras, you deal with the feel of the source."

The technique of following source has now become a standard approach in many dramatic productions.

To do this a lighting director must first determine where the sources of illumination might be within a scene. They may be visible, or just suggested by the setting.

If no sources are obvious within the scene, you then decide where logical sources of illumination might be.

In a poolroom scene, for example, the light source might be a light above the pool table—even though it might not be visible in the scene. It then becomes a matter of keying important camera closeup positions so that they are consistent with this suggested source of illumination.

Drawing A Lighting Plot

Part of the preproduction process involves carefully thinking through your lighting design.

In positioning lights considerable time is involved in climbing ladders and then hanging and connecting lights. To reduce the problems involved you need to plan out the whole effect with a paper and pencil or a computer drawing program before you start.

If you are lucky enough to be able get someone else to actually hang the lights in the studio for you, you'll still need to have a way of indicating where you want each one placed. But even if you must hang the lights yourself, having it all planned out on paper will save you time and trouble.

In either case you will need to draw a lighting plot with all of the lights and their positions noted.  Most production facilities will have a basic lighting grid form for their studio that you can use as a starting point.  Here's an example. 

Studio drawings should include the grid lines shown above.  Note that any lighting position can be indicated by a letter and number designation. For example, position "J-7" ends up being in the middle of this studio.

Once the lights are hung, they can be plugged into electrical  outlets — typically near the grid pipe cross-points — and the lights can be programmed into a lighting control system to be remotely switched on and off or dimmed.  

The typical three-prong, locking twist connector used for connecting lights is shown on the right.

Setting Up Lights

In the studio, lights are commonly attached to a lighting grid with C-clamps and safety chains. On-location lights are normally mounted on floor stands. A portable lighting kit is shown on the right.

Key and fill lights are generally easy to position; stands are just placed at 45-degrees on either side of the camera at an appropriate height.

On locations, back lights can't be hung from a lighting grid as they can in a studio, so other solutions must be considered.

A back light may be clipped to the top of a bookcase, an exposed rafter, or any convenient, out-of-view anchoring point. If this option isn't available, you might consider constructing a lighting goal post out of black plastic (PVC) pipe over the background area (outside of the camera's view) and clipping the light to the center. One or more back lights can be hung from the middle and the wires can be taped to the pipe with black electrical tape.  
 

Lighting Boards

Typically, dozens of lights are required for each studio setting. In an elaborate dramatic production involving several sets (all of which may have to be ready for use at the same time), there can even be several hundred lights involved.

Being able to control all of these lights—switch them on and off, dim them to required settings on cue, etc.—can be a daunting process. 

Although simple lighting boards such as the one pictured on the left can handle basic studio productions, major dramatic productions require a computer-based system.  

Typically, a software program displays each of the ceiling grid connectors on the computer screen.  (Note the photo on the right.) You will recall from an earlier illustration that any grid lighting connector can be indicated by a letter and number combination.  After a lighting instrument is plugged into one of these connectors, power settings can be programmed into the computer.

Once this is done, the lights can be assigned to groups and all controlled together.  For example, switching an interior scene from a daylight to a night effect may involve simultaneously dropping the level of the background and fill lights, and eliminating several key lights. 

Once all the lights are programmed, scene and time-of-day changes require only a few mouse clicks to activate preprogrammed settings.

On-Location Power Issues

In setting up on-location lighting it's often necessary to figure out how many lamps a fuse or circuit-breaker can handle.

Although the standard house current voltage in the United States and many other countries is between 110 and 120, in doing calculations it's common to assume a voltage of 100. This not only makes it easier to do calculations, it automatically provides a safety factor. By assuming a voltage of 100, the following formula can be used:

watts divided by 100 = amps

(The standard voltage in your country may vary, and the base of these calculations will have to change accordingly.)  Assuming 100 volts, and using this formula, a 500-watt lamp would draw 5 amps. A 20-amp fuse or breaker could handle up to 2,000 watts; a 30-amp fuse up to 3,000 watts, etc.

When setting up multiple lights the total wattage is simply added together. If a 1,000-watt key light, a 500-watt fill, a 500-watt back light and a 500-watt background light were all plugged into the same circuit, the combined amperage (which comes to 25 amps) would blow a standard 20-amp fuse or breaker. (Actually, it might take a few minutes to heat up the breaker enough to trip it—just long enough to get a good start on taping a segment!)

To keep from overloading a fuse or circuit breaker, it's often necessary to run extension cords from separately fused circuits—possibly from an adjoining room. But if these extension cords are not made of heavy gauge wire they can lower voltage to lamps, resulting in drops in color temperature.

Since power (total wattage) in some locations is limited, you may have no choice but to bring in an electrician to run a temporary, high-amperage line from the main fuse box. In remote areas a generator truck or a portable, gas-powered generator may have to be considered.

Film vs. Typical TV Lighting

Compared to dramatic film scenes, video (especially sitcoms, game shows, etc.) often looks a bit flat and dimensionless. Although some people conclude from this that video is inferior to film, the reason actually centers primarily on differences in lighting.

Since film is almost always shot in single camera style, lighting angles and intensities (not to mention audio, make-up etc.) are optimized for this one camera angle and distance.

A typical television sitcom involves three or four cameras spanning almost 160-degrees. Since the director needs to be able to cut to any camera at any time, the lighting must be able to hold up throughout this entire range.

To avoid the possibility of having major shadow areas, the safest way of lighting this type of production is to light relatively flat (high-key) using multiple key lights to cover every camera angle. This means that dimension and form are lost, the things that can make film scenes seem much more dramatic.

But, if the time and budget allow, video can also be shot single camera, film-style. When this is done, video—and especially digital/HDTV—can achieve the same dramatic quality we're used to seeing in film.  

The Art Of Lighting

In describing the basic techniques for lighting in these modules, we've covered approaches that will provide good results for most studio and field work. At the same time, no attempt can be made to cover complex lighting needs. Numerous books have been written on this subject alone.

The lighting required for sophisticated, multiple-camera dramatic productions requires the skill and artistic ability of an experienced lighting director. At this level of sophistication lighting moves into the realm of a true art form.  

In the next section we'll turn to the audio part of the TV medium.