Lasers In Churches

In Uncategorizedby tfwm

From the first chapter of Genesis, to the last chapter of Revelation, light is featured prominently in the Bible. The first words spoken by God are “Let there be light”; His first act is to bring forth day and night. In Exodus, an angel appears to Moses as a bright burning bush, and later God creates a pillar of light to guide the nighttime travelers. In the New Testament, the birth of Jesus is heralded by the most famous star in history. In Matthew 17, Jesus on the mountaintop “was transfigured before them, and his face shone like the sun, and his garments became as white as light.” Similarly, on the road to Damascus, Jesus appears to Paul as “a light from heaven, brighter than the sun.” Also, throughout the entire Bible, light is used as a metaphor to represent guidance and wisdom, as in Psalms 27:1: “The Lord is my light and my salvation.”

For this reason, church productions looking to portray Biblical light – either literally or metaphorically – are turning to the purest, most concentrated form of light: lasers. In recent years lasers have become easier to operate and more cost-effective. Uses can range from basic, where the laser’s intense beam of light is used by itself, to sophisticated, where computers control the beam’s trajectory in order to project images and words.

One church that used lasers in its productions is the Free Chapel Worship Center in Gainesville, Georgia. Jim Martin of Peachtree Laser explains, “The Pastor asked if we could make the ‘writing on the wall’ from Daniel 5:5 appear to be written on stone. We laser-projected God’s hand and made its finger write out “Mene Mene Tekel Upharsin” onto an onstage rock. Later in the same service, we projected beams and animated aerial effects during the appearances of singers while they bowed before Jesus and flying angels.”

Evangel Church of Upper Marlboro MD, a congregation of about 5,000, has featured lasers in their annual Christmas show for the past six years. Image Engineering Inc. chose white-light and green lasers for the shows, which have been seen by as many as 20,000 people each year.

These churches are taking advantage of one of the technological marvels of our time – the laser. Light-creating lasing action was first described by Albert Einstein in 1916. But it wasn’t until 1960 that the first working laser appeared.

Laser light is special in a number of ways:

• It is spectrally pure, so the color of any given beam is as intense as possible. For churches, this purity and intensity is a perfect metaphor for the Lord.

• The light is coherent, making for an impressive pencil-thin beam of light.

• This coherence also causes the light to sparkle and shimmer, an ethereal effect called “laser speckle”.

• An array of laser beams (created via optical effects) creates awe-inspiring rays and fans of light.

• Since the projected laser is a tight dot, computer-controlled mirrors called scanners can be used to draw images as in the “writing finger” effect described above.

By combining these characteristics, the unique benefits of lasers become apparent. Consider creating a laser Star of Bethlehem. Even a simple laser “dot” from a moderately-powered laser would appear brighter than any other light on stage, and would have the dazzling laser speckle. (Incidentally, the bright and dark spots of the speckle occur not at the light source or projection screen but at the viewer’s eye. This means those with far- or nearsightedness can take off their glasses and still see the speckle just as sharp.)

There are many other effects that can be done with the Star. For example, shining the beam through rotating diffuse plastic causes an eerie aura of laser light making it look more like a supernova. A dramatic beam can come directly from the Star onto the manger (although of course the beam cannot shine directly on an actor’s face). If laser-computer graphics are used, the Star can be drawn out, and animated with pulsating rays. There are literally dozens of ways to make an awe-inspiring, laser Star of Bethlehem.

Why have lasers not been used more? Until recently, the laser unit itself was difficult to integrate into productions. In the past, a typical laser with sufficient visibility for an audience of 100-1000 would require 240 or 480 volts, and two gallons of water per minute for cooling. Today, however, new solid-state lasers about the size of a loaf of bread have emerged. These are literally “plug-and-play”, using standard 110 volt AC power and simple fans for cooling.

Even the largest secular shows now use these diode-pumped solid-state (DPSS) lasers. At the new Universal 360 nighttime show in Orlando, eight DPSS lasers arranged around a lagoon fill the sky with multi-watt beams. Each projector – including laser, computer, scanners and weatherproof housing – is the size of a small air-conditioner. Previously, each projector would have required a roomful of equipment.

Just as the laser itself has become smaller and much easier to use, the additional projector components also have been simplified. For very simple effects, holographic diffraction gratings (HDG) can be used to create beam arrays and even simple dot-pattern graphics.

Many laser effects are literally “done with mirrors.” A mirror scanner consists of a tiny (1/4” square) mirror mounted on a rotating galvanometer shaft. A voltage input causes the shaft to rotate and thus the beam to deflect. Two such scanners are mounted at right angles, so that one mirror rotates to deflect the beam horizontally; this then reflects off the second mirror, which moves vertically.

There are many inexpensive disco-type laser projectors using low-cost scanners and basic signal sources, to create sequencing beam patterns and abstract oscilloscope-type graphics.

For more control, high-end projectors use precision feedback scanners under computer control. Laser graphics are stored in the computer as a series of X-Y points to be traced. The computer outputs two voltages to control the scanners, turning the mirrors so they step through the points. This is done fast enough (>20 scans per second) so the resulting projected outline image appears solid and not flickering.

The computer-controlled shapes can be projected onto just about any surface, to create logos, drawings, animations and words. Lower-cost graphics projectors come with pre-programmed imagery. The most sophisticated systems include drawing software so you can make your own custom images.

The system used at Free Chapel is typical. For the “moving finger” effect, two basic frames were required. A program called Lasershow Designer 2000 was used to draw the hand of God, and to type in the words to be projected. The hand frame was then “attached” to the frame with the text, so that the finger would follow the path of each letter. Finally, the text was drawn out, point-by-point as the hand frame followed. To the audience, it looked as if the moving finger was writing the text on the rock, leaving the glowing letters behind.

Projected images are one of the two main types of laser displays. The other type uses the beam as an artistic element, usually in conjunction with theatrical haze or fog.

The beam can be used alone, as in the Star of Bethlehem-to-manger scene described earlier. By using linear or grid diffraction grating, the beam can be split into multiple beams to create a fan— perfect for heavenly radiance. A cylindrical lens causes the beam to spread into a line. This creates the classic “laser ceiling” where a thin cross-section of theatrical fog swirls above the audience’s heads. This effect would look ominous in a context such as depicting the tenth plague of Exodus, where a widening laser ceiling represents the Angel of Death spreading throughout Egypt on Passover.

The ultimate beam show is done by using the same computer-controlled graphics projector as described earlier. The projector is simply placed so it is aimed over the heads of the audience, and theatrical fog is introduced. The computer-controlled graphics cause precisely-timed flashing beams, planes and cones of light, and shifting shapes to dance above the audience.

Just as projectors have different capabilities, the underlying lasers also come in different powers and colors. In the powers needed for indoor shows (roughly 1 to 10 watts), green is the easiest color to produce. Single-color red or blue lasers would cost more than a green laser of equivalent power. The ultimate is a laser which combines red, green and blue beams into a single “white light” beam. By varying the mix, over 16 million different colors can be created. This is perfect, for example, to project a computer-drawn rainbow graphic or a multi-colored fan of beams in a show about Noah and the ark.

For some churches, laser beam and graphic effects may be used frequently enough to justify purchase of the laser projection equipment. Other churches may prefer to bring in laser light show specialist companies. One information resource, for both equipment and rental companies, is the International Laser Display Association

A question which is sometimes asked, is whether the laser can cut or damage materials. The types and powers available for theatrical productions are actually quite safe. Just use simple, common-sense precautions, such as taking care to keep the direct or reflected beam away from viewers’ eyes and faces. Any projector purchased should be varianced (approved) under U.S. law. A laser show company can help with any federal and state paperwork that may be required to initially set up the laser show.

In the past, laser equipment has had a reputation for being difficult to use, and hard to program. But recent advances in solid-state lasers, integrated into theater-friendly lighting instruments, are making inspirational effects much more feasible for church-scale productions. This can be done through laser display companies (rental) or by the church itself (purchase).

The benefit of using lasers is the ability to inspire viewers. Today’s audiences are constantly exposed to such stagecraft as lighting fixtures and large-screen video. However, lasers are still relatively rare and thus have much more of a “wow” factor when they appear. The Bible is full of miracles and wonder. Laser light, the purest, most precise illumination known to man, is perfect for bringing miracles and wonder to life.

Patrick Murphy is executive director of the International Laser Display Association (ILDA), based in Orlando, Florida. Founded in 1986, the ILDA is the world’s leading organization dedicated to advancing the use of laser displays in the fields of art, entertainment and education.