UV or black light makes things glow in the dark.
Blacklight, more accurately Ultraviolet (UV) lighting, effects are created by exposing UV sensitive materials to a narrow band or spectrum of invisible light waves. The materials glow or fluoresce when struck by the specific light waves. Some materials (such as paint pigments) are invisible until exposed to the UV spectrum.
UV Lighting Sources
A wide variety of UV fixtures (or instruments as they are called in theater) are available for sale and rent. You are probably most familiar with the blacklight tubes and bulbs found in general retail stores. These are available at Home Depot and other lighting stores and often, during Halloween, at department stores. However, these are not industrial (theater) grade lamps. Low wattage---and therefore, short throw distances---make them almost useless. Most of their energy is spent in heat and the filaments produce very little of the UV spectrum.
UV: How It Works
UV actually comes from the invisible part of the light spectrum (about 280 to 400 nanometers); it is beyond the color violet seen by the human eye. Incandescent bulbs and fluorescent tubes actually use a purplish glass which filters out much of the unwanted light allowing only certain wavelengths (violet and ultraviolet) to escape. However, they do not filter enough of visible light to provide total darkness to the human eye. Newer, specialized lamps (what are called bulbs in the theater) produce more UV and reduce the level of unwanted visible light wavelengths.
Professional UV Instruments
Several theatrical lighting manufacturers offer a line of powerful UV instruments including tube and LED lighting as well as mercury vapor (which emits the most light in the UV spectrum). These can be expensive to purchase, but rentals tend to be reasonable. Makers include Altman, Wildfire, ZCR and UVFX among others.
UV Sensitive Materials
UV sensitive pigments are available in dyes, paints, plastics and make-up. Most florescent (day-glow) fabrics found in clothing and fabric stores will respond to UV light in the dark. The same is true for day-glow paints and other products. Sunlight contains UV light and that's what gives day-glow products their brilliance on the street. In fact many laundry detergents contain day-glow brighteners that make fabrics seem more vivid.
There are also pigments that are invisible under normal incandescent light, but show up under UV. Therefore a mural can be painted to appear differently under the two light sources (see examples at uvfx.com). Several theme parks including Disney and Universal use blacklight effects in what they term dark rides (i.e., Pinocchio, Mummy). You can see these on YouTube.
UV Effects Ideas
In a theatrical presentation performed in theater blacks against a black background the performers are virtually invisible. Only the items (costumes, props, puppets, make-up) made up of florescent materials are visible and can appear and disappear at random simply by veiling or unveiling them in black cloth. Disney uses a variety of blacklight effects in stage shows involving puppets (like Finding Nemo at Walt Disney World and Fantasmic! at Disneyland). Again, videos of these shows are available at YouTube.
Stage shows involving dancers (wearing florescent clothing and make-up) in the dark or, say, drummers performing on various percussion instruments are effective uses of UV. The instruments can highlighted with florescent tapes and drumsticks made of glow-in-the dark fiberglass work well. All glow-in-the dark materials are also activated by UV light. Type Blue Man Group drumming with paint into YouTube.
Shows involving performers in white gloves motioning and clapping rhythmically are also quite cool. White materials glow a pleasant blue under UV light. Performers dressed in black and sporting white gloves can also form images the way the school of silver fish do in Finding Nemo. Type white gloves in blacklight into a YouTube search.
Use Your Imagination
A number of effects houses---like Wildfire and uvfx---also sell florescent materials in the form of streamers, liquids, plastic beads, flexible PVC tubing and the like. UV effects are used in clubs, theme parks, theater, museums and retail. Use your imagination and come up with more creative ways to utilize these products.
Tags: blacklight, effects, white gloves, Finding Nemo, florescent materials, glow-in-the dark, into YouTube, light spectrum, light waves, materials glow
