The term "light curtain" covers a variety of stage lighting effects, ranging from starry night backgrounds to tricks that make some objects easy to see while obscuring others. Such curtains range from low-cost, do-it-yourself light curtains made from recycled materials to high-end, fibre-optic backdrops custom sized for a particular stage. The right type for your special event or performance depends on the effect you want to present.
Star drops are one of the most popular light curtains for stage events. These backdrops use black cloth that provides the "night sky" look, and then hundreds to thousands of tiny lights are embedded in the cloth to create the appearance of stars. Another common style of light curtain is simply a curtain of hanging string lights, either in a single colour or variety of colours, which creates the look of a lit curtain, adding a festive atmosphere to the event. Puppeteers and other performers use a third type of light curtain, less common in other events, which consists of bright light shining across a darkened stage. When puppets are placed within the light beam, they become visible, while everything behind the beam, including the puppeteer, remains unseen.
You can make a simple star drop out of a large, heavy piece of black fabric and white string or Christmas lights. Use fabric that is entirely opaque, and make sure it is flame-treated to protect it from any electrical shorts. Snip small holes in a random pattern throughout the fabric, and then poke just the tips of white string lights through the holes. Pin or tape the lights in place. When plugged in, the lights will appear like stars from the front of the curtain. Intermix solid with twinkling light strings--approximately one twinkle string for every three solid-on strings--to get a twinkling star effect. Fibre-optic and other professional-quality star drops offer more control than the homemade variety, but are expensive to purchase. If you need one for a one-time event, inquire at your nearest theatrical supply store about renting a star drop. If you have no local supplier, many large companies in New York and Los Angeles will ship you a rental drop.
String light curtains that consist of multiple vertical strings are nearly always do-it-yourself projects. For this type of light curtain, measure the width of your stage, and then divide that by the number of light strings you want per foot to determine the number of light strings you need. LED light strings work best for this purpose, as you can attach many more strings to the same power source due to the low power consumption. Large stages look good with one light string every 6 to 12 inches, while small stages less than 30 feet wide may need a string every 3 to 6 inches to avoid having the curtain look sparse. This light curtain style is great for celebrations with colour themes such as sporting events or graduations because you can choose light strings that reflect your colour theme.
The light curtains used by puppeteers, magicians and some theatrical performances require a strong, highly controlled light source. Puppeteers often use two lights, one shining from either side of the stage from a low angle. Other applications use strips of lights that shine down from above, allowing the light to mask entrances and exits and create a virtual backdrop. Rosco, a theatrical equipment and supply company, offers lights specifically designed for the latter purpose, called "Digital Light Curtains." These lights offer added versatility through colour changes and movement.
For any kind of light curtain, check the power consumption in watts before you plug it in. Make sure you have at least that much wattage available on your circuit so you avoid blowing a fuse or breaker. Stage circuit power allowances vary by venue, so check with the house electrician or maintenance staff to find out what power is available for your use.