LED Light Tricks

Light-emitting diodes, or LEDs, are bright, compact, use little energy, create little heat, have a long life, and are all the rage. LEDs seem to be the ideal lighting product. They're perfect for a wide range of theatrical effects as well. You are about to learn three great tricks using LEDs and simple materials to create sky illusions.

Creating an LED Star Curtain

• This effect creates the illusion of a starlit night sky. You will need a large black cloth, a hot glue gun, a knitting needle, and several strings of white LED Christmas lights. I recommend Commando Cloth, which is inexpensive and can be found at many theatrical supply houses. It's durable, fire-retardant and very nonreflective.

  1) Begin by sewing the fabric into the dimensions you require. Be sure to calculate for and sew in the pipe pockets for hanging.

  2) Poke a hole in the fabric from the back side with the knitting needle and push the first LED lamp into the hole. Secure it there firmly with hot glue. Don't worry about covering some of the lamp; variations in light intensity will make the "stars" appear more real. Try to keep the glue off the front of the fabric.

  3) Repeat this in a random pattern until you run out of LEDs on the first string. You don't have to stick every LED through the fabric if you wish to have a greater distance between stars and clusters.

  4) Use a another string and mix them in with the lights of the first string. Remember, LED strings on different circuits can be dimmed to different brightnesses. You can even make them twinkle if you like.

  I recommend at lease one string of 100 LEDs for every 100 square feet of fabric, depending on how dense you like your star field.

Make an LED Shooting Star

• This effect creates the illusion of a shooting star across a star field.

  1) Pick up a cheap, single LED flashlight from your local hardware or variety store (you might even find one at a dollar store). Open the housing and take the thing carefully apart. Discard the housing and lens. Retain the batteries, LED, and switch system. You may use whatever battery comes with the product, but I recommend button batteries over AAs. You will also need some black electrical tape and a paper clip.

  2) Rewire the pieces together to create a circuit that can be opened and closed by the switch--batteries, switch, LED, and back to the battery. Secure the terminal wires to the batteries with tape, secure the batteries together with the tape, and then secure the switch to one side of the battery pack and the LED to the other side.

  3) Bend the paper clip into an S and attach the large end to the device, leaving a hook. Make sure that all parts of the device (except the paper clip hook and the switch) are covered in black tape.

  To shoot your shooting star, you will need to stretch some fishing line from a high point off stage on one side of the proscenium to a low point off stage on the other side. Hook the device over the line on the high side, switch it on, and let her go. Capture and switch off the device once it crosses the stage.

Using LED PARs to Light a Scrim Cyclorama

• This effect will create the illusion that your night sky (star curtain) is fading into dawn (or in reverse to dusk).

  Terms:
  LED PARs lights are a type of theatrical fixture that creates a soft flood. They are made up of numerous LEDs housed in an array. For this effect we will want RGB fixtures that contain red, green and blue LEDs so that the colors--each on their own circuit/channel--can be mixed to achieve a desired hue.

  A scrim is a fabric drape made up of an airy, gauze-like fabric. When lit exclusively from the front, it appears opaque. When you light objects behind the scrim while it is lit from the front, the scrim appears translucent. When you remove the front lighting, the scrim becomes almost invisible. Scrim comes in white, black, and blue.

  Here's what you do:
  1) Hang your scrim drape about 1 ft. or so in front of your star curtain. Black will be the most invisible, but it will not pick up the the colored lighting well. White and blue will be nearly invisible while you keep front lighting off. Minimize lighting spill to keep the scrim invisible.

  2) Hang a number of LED PARs in a way that will evenly light the front of the scrim. I suggest that you light from the bottom (hiding the fixtures behind a ground row because the sun rises and sets from the horizon). You can also light from the top down using blue-gelled conventional fixtures. Maybe even add in some cloud gobos, which are metal pieces attached to lights to project a pattern.

  3) Use your lighting controller to fade through the desired hues--purple to magenta to blue or orange to red, to purple--to create the sunrise/sunset illusion while you fade the stars in or out.

   Read more http://www.bgocled.com/