The DC carbon-arc fresnel is falling into disuse since the advent of the HMI. For many years, the brute arc was the “big mama,” the heaviest hitter. With many times the output of the 10K, it was the standard for fi ll to balance sunlight, the major workhorse for night exteriors, and sun effects through windows.
Invented by Sir Humphrey Davy in 1801, the arc was the fi rst high-intensity electric light. It was used in theaters and then adopted by the fi lm industry as the only source bright enough to use with the extremely slow emulsions then avail- able. It was the only artifi cial alternative to the all-glass or all-skylight studios that were necessary.
The arc produces light by creating an actual arc between two carbon electrodes. As the arc burns, the negative and positive electrodes are consumed and so have to be continu- ously advanced to keep them in the correct position. In modern arcs this is done with feed motors. In the early days, the electrode feed mechanisms had to be turned by hand. This called for considerable experience on the part of the
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Lighting Sources 17 technician, and the term lamp operator was applied to the
most skilled electricians. Even today the name is used on some older studio budget forms to describe set electricians.
The other reason is the gigantic power consumption of arcs (225 amps for the standard brute, which calls for a #00 cable run for each light) and the fact that it must be DC, which dictates either a studio with DC or a large DC generator. The bottom line is that, even with a very cheap daily rental, the arcs are more expensive to operate than an HMI. The arc was particularly useful in that it could be daylight- or tungsten-balanced without gels, something that no other light could do until fl uorescent units with changeable bulbs came along. This is accomplished by using either white-fl ame carbons (daylight balance) or yellow-fl ame carbons (tungsten balance).
For daylight-balanced use, the white-fl ame carbons run high in ultraviolet, and a Y-1 fi lter is usually added to coun- teract the UV effect. MT-2 converts the white-fl ame carbons to tungsten color balance. All arcs have an ancillary piece of equipment called a grid or ballast. The grid serves two pur- poses. It is a giant resistor that limits current fl ow across the arc and reduces the voltage to the optimal 73 volts without reducing the amperage. For arc operation, see the Appendix.
Open-Face Lights
Lights with fresnel lenses provide a higher degree of con- trol and refi nement—smoother and more controllable with cleaner shadows. Open-face lights have no lens and are less controllable, but they make up for it by being far more effi - cient: an open-face light will be far more powerful than an equivalent-size fresnel light. Open-face lights are generally
FIGURE 2.5 A side-by-side comparison of a Brute Arc (on the right) and a 12K HMI PAR. Both units are mounted on Mole Litewate crank-up stands.
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18 Motion Picture and Video Lighting
better for when just raw power is needed, such as bouncing the light or going through heavy diffusion.
Skypan
The skypan is simple in design. It consists of a refl ective white pan with a heavy-duty lamp socket positioned to keep the bulb at the center of the refl ector. Most have a switch on the back. The skypan is used primarily when just raw power is needed over a fairly large area, such as lighting a large backdrop. There is only one fl avor of skypan but either a 5K bulb (DPY) or a 2K bulb (CYX) bulb can be used in it. When ordering, don’t forget to specify bulb size and remember that this will affect your cable order and your power con- siderations. Only two basic accessories are available for the skypan: a skirt that does control some of the side spill (and is useful for keeping direct hits out of the lens) and a gel frame. You usually won’t get them unless you specify in the order.
2K Open Face
The 2K open face is a real workhorse. Mole’s version is the Mighty-Mole, Ianiro’s is the Blonde, and Arrifl ex also has a version. Its open-faced design provides far greater output per watt than a 2K fresnel, making it the light of choice for bounce sources. If going through diffusion, it can also be a direct source. Mightys are used in book lights, frog lights, and as backlight illumination for tissued windows, tented prod- ucts, etc. Most versions have a collar that clamps on the front of the light and provides the support for the barndoors, gel frames, or scrims.
1000-/600-/650-Watt Open Face
Mickey-Moles (Mole–Richardson) and the Redhead (Ianiro) and 1K Arrilite (Arrifl ex) are the little brothers of the 2K open face and differ only in bulb (1K) and size. They are great as small bounce sources (such as an umbrella light for portraits), small-fi ll bounces, and for just sprinkling a little light on background objects. Their small size (especially the Redhead, which is remarkably compact) makes them easy to hide in the set. The 650- and 600-watt baby sisters are even smaller and fi nd use in Electronic News Gathering (ENG) and small unit video production. With a bit of diffusion they are often attached to the top of the video camera as a travel- ing fi ll light.
Lowell makes the lightweight, highly portable DP Lite that is often used in small video and ENG production. Like all Lowell lights, it has a wide variety of clever and well- designed accessories: snoots, barndoors, snap-on fl ags, dichroic fi lters, etc. Lowell’s Omni Light is a smaller version of the DP and has the same range of accessories. It is an (a)
(b)
FIGURE 2.6 MolePARs (firestarters) (a) With a stippled bulb (Narrow Spot); (b) with a clear lens (Very Narrow Spot).
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Lighting Sources 19 inexpensive unit and provides basic open-faced light or can
be used as a self-contained umbrella bounce.
PAR 64
PARs are raw light power in its most basic form (it is all cap- itals because it stands for Parabolic Aluminized Refl ector). Cousins to auto headlights, they are sealed beams of light (combined bulb, refl ector, and lens) available in a wide vari- ety of sizes and beam spreads. One of the most commonly used is the PAR 64 1000 watt. Eight inches across (64/8 of an inch), they employ a highly effi cient parabolic refl ector that is capable of projecting the beam with very little spread.
A completely clear lens for a PAR is called a very narrow spot (VNSP), and with a light texture it is a narrow spot (NSP). This makes them useful for hitting distant background objects that cannot be reached otherwise. With a stippling effect on the lens, the light becomes a medium fl ood (MFL) and spreads the same amount of light over a broader beam. With a more pronounced stippling, the light is a widefl ood (WFL) with an even greater beam spread. Because PARs have a long, thin fi lament inside the refl ector, the beam of a PAR is oval rather than circular. This can be a useful feature as the beam can be oriented to “fi t” the subject.
PARs are remarkable for their effi ciency. A narrow spot 1K PAR, measured at the center of its beam, generates an output comparable to a 10K measured at the center of its beam. The trick, of course, is that it covers only a very small area, but it may be suffi cient for many purposes such as high-speed table top or punching of light through heavy diffusion.
PARs come in two basic varieties. Film versions come in a solid rotary housing such as a MolePar, which feature barndoors and scrim holders, and in a fl imsier theatrical
(a)
(b)
FIGURE 2.7 (a) PARcans used as downlights create hot pools of light in this scene from X-Men. Kino Flo units are a big soft source over the fi ght ring. When the camera is looking up, they appear in the scene: an advantage of lights that don’t necessarily appear to be “movie” lights. (Photo courtesy of Tony “Nako” Nakonechnyj.)
(b) Skypans in use on a set, in this case suspended above silks to give a set an overall soft ambient light. (Photo courtesy of Mole–Richardson Co.)
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20 Motion Picture and Video Lighting
version called a Par can—very popular in rock and roll con- cert lighting. Most versions allow for the bulb to be rotated freely to orient the oval beam. Many DPs refer to this unit as a “fi restarter.”