PAR's are the most common and least expensive type of lighting instrument theatres use. They are very, very popular with small touring shows, or especially with bands that play in small spaces, such as bars.
They are called P-A-R's because of the type of lamp used. They use Parabolic Aluminized Reflector lamps. These are the similar to the floodlights you might find as outdoor spotlights on a house. Thus, the lamp contains the bulb, the reflector to direct the light forward, and the lens for disbursing the light all in one unit. This means the instruments you see pictured here are nothing but "tin cans."
They have no shutters or any substantial control mechanism. You can, however, install gels in the gel holders.
Thus, the reason they are so cheap is that the instrument has virtually nothing to it - all the expense is in the lamp - PAR's use specialized lamps only available at theatrical supply houses. These lamps cost about $25 to $30 each and you can actually buy different lamps with different lenses that shape the beam of light. There is a Very Narrow Spot (VNSP), a Narrow Spot (NSP), a Medium Flood (MFL), and a Wide Food (WFL). These various Lamps come in 300, 500, or 1000 Watts depending on how bright you need them to be. One 1000w PAR will light an entire stage bright enough for rehearsal purposes.
The real downside to these instruments is the lack of control one has over the light, and they cannot throw light very far without spreading too wide; thus, for a theatre like ours and most full size theatres they are not very workable, except for general broad washes of light. You can put a set of barn doors on a PAR and get a little more control over spill.
