Identify the instrument based on location. Large follow spots, or what we think of as spotlights, are usually positioned to the rear of the theater and above the seating area, often in "crow's nests" above the floor. Intelligent lights, instruments that move and operate by remote control, are positioned over the audience area as well as over the stage. Large ellipsoidal and Fresnel instruments, which can produce a focused beam of light, are typically mounted over the seating area. Smaller ellipsoidals and Fresnels can be found hanging from pipes or trusses directly over the stage or inside coves just outside the frame of the stage. PAR "cans" and scoops are mounted near or over the stage to provide broad washes of light. Border lights are usually set in long box sets and also provide washes of light over the stage: old-fashioned footlights are actually border lights placed on the floor. Cyc, or cyclorama lights, are mounted at the back of the stage, either on the floor and/or overhead, and used to light a hanging background drape.
Identify the instrument based on type of lens. The Fresnel lens is easily identified by its circle of ridges or "stepped" lens. Of all the instruments with stage lighting lenses, this is the one we most often associate with the theatre or movies. No other instrument has a stepped lens. This lens can be focused to produce a soft- or sharp-edged pool of light. PAR cans, scoops, cyc and border lights have no lens at all. They are instruments intended to wash or flood the stage area, usually with color. Intelligent lights and ellipsoidals have a smooth, curved lens that can be very crisply focused or broadly softened in creating a pool of light. Both intelligent lights and ellipsoidals can be fitted with a pattern-holder that can project a texture or image on the stage. The follow spot has a smooth lens that can also be precisely focused.
Identify the instrument based on shape. The shape of stage lights gives a clue to its function. Most follow spots are very large, barrel-shaped instruments that rest on a stand with a yoke so they can be pivoted easily. Intelligent lights are shaped like orbs mounted on a rotating yoke. Some ellipsoidals have a shape like a Coca-Cola bottle, while others are shaped like a long flower box. Fresnels are shaped like a can, as are PAR instruments. Scoops look like a rounded salad bowl, turned upside down. Border and cyc lights are mounted in long metal boxes or troughs.