One of the oldest types of lighting instruments, fresnels are named for the lens they use, which was invented in 1922 by Augustin Fresnel and is commonly used in lighthouses. Fresnels are considered wash fixtures (even when sometimes colloquially called "Fresnel spotlights") due to their soft beams, and have spherical reflectors that direct the lamp's light toward the front of the instrument. Theatrical fresnels are measured by the diameter of their lenses and commonly come in 6-, 8- and 12-inch sizes. They accommodate lamps ranging from 500 to 2000 watts, and specialized fresnels for the film industry can accept up to 6000-watt lamps. The beam control on a fresnel consists of a crank or nut assembly that can be used to slide the lamp toward or away from the reflector at the rear of the lamp's housing, resulting in a smaller or larger beam.
Parabolic aluminum reflector (PAR) lighting instruments are one of the most common lighting instruments used in concert and general lighting because they are comparatively inexpensive and produce a bright light that can project long distances. As the name implies, the reflector that directs the lamp's beam is parabolic in shape, which produces a soft-edged beam that is oblong. The lamp itself is the primary component of most PARs, consisting of a self-contained unit with a reflector, lamp and lens all in one, similar to household flood lamps. The housing of the lighting instrument is a simple cylinder with a rounded back, except for some newer PARs that have different configurations. These instruments come in a variety of sizes, ranging from a PAR-16, a miniature light sometimes used inside set pieces, to a PAR-64, the most common type of PAR, which usually uses a 1000-watt lamp.
Ellipsoidals or ellipsoidal reflector spot (ERS) instruments are highly adaptable profile fixtures that use an ellipse-shaped reflector and a series of lenses to produce a variety of beam sizes that can be controlled to produce sharp edges and project patterns. Standard ellipsoidals contain, from the back of the instrument working toward the front, a reflector, a lamp, a shutter assembly that uses four sliding metal panes to shape the light into straight lines and angles, a pattern slot where metal or glass patterns can be placed so they are projected, and a barrel, which holds one or more lenses that shape the beam into a focused circle. Adjusting the barrel toward or away from the body of the instrument softens or sharpens the beam. While often used for general lighting because they can be easily controlled, ellipsoidals are most common as specialty lighting instruments for color, patterns and shapes. They are occasionally referred to as "Lekos," after a brand name that was once the most common.
Intelligent or automated lighting is a more recent development in the lighting industry, gaining popularity throughout the 1990s and early 21st century. Automated lights often have internal color changers and pattern holders that can swap out patterns as well as rotate or perform other movements. The beams themselves may be controlled by a movable mirror, allowing the light board operator to move the beam across the stage. Sound activation and programmable effects are also common in automated lighting. Most automated fixtures are profile fixtures to allow greater beam control. Simpler wash fixtures may feature automated "yokes," which allow the light to pan and tilt due to electronic control of the assembly it hangs from (the yoke).
Companies such as ETC and Altman in the U.S. and Selecon in Australia are constantly developing new lighting instruments. LED color-changing lights, lower wattage halogen lamps, combination PAR-fresnels and low-heat lights that can accept patterns printed on acetate from a computer are some of the early 21st century developments these lighting companies have created. Other, more classic, instruments in addition to those listed include followspots, which are large profile fixtures that are manually controlled to follow moving performers, and cyc lights, which use specially shaped reflectors and halogen tube lamps to create bright, far-reaching wash-style light to illuminate backdrops.