Piratecat said:
Now you're just making words up.
No he isn't. A gobo is a piece of metal inserted into a type of light called a leko (not liko), which I didn't see on the boom but I'm fairly certain the convention center has a few in stock. In a theatre show leaf patterns or shafts of light a'la a doorway or window can be projected onto the walls and floors of the stage area using a leko fitted with a gobo.
The three primary theatre lights are Lekos, fresnels, parcans. There are others - scoops, strip lights, for example, but those aren't used as often.
Lekos have two lenses in them. The name is a contraction of the inventor's names (which escapes me at the moment). These lights create a very crisp, defined lighting area if that is desired, or they can create diffuse light as determined by the distance between the lenses (which is adjustable) They have shutters to control the radius of light that is thrown on the stage or to add an edge to it to prevent light from spilling onto unwanted areas such as the house wall and proscenium. They can be fitted with gobos as mentioned above which are really just pieces of metal with holes cut in it. Leko's come in various sizes which are rated by the distance they can reliably throw light. 15', 30' and 60' are the most common, though 90's and 120's are not unknown, especially in operas. Leko's are the theatre's most flexiable light, but also the most expensive, at anywhere from $600 to $1200 each.
Fresnels tend to be smaller and are named for the inventor of their lens. They throw a wide but diffuse and "soft" light. Fresnel lenses are used on lighthouses today and where used on the very earliest of cars and trains. In a steampunk setting a bullseye lantern could be fitted with a fresnel lens - consider this a masterwork touch that doubles the throw distance of the light (THERE, I worked D&D into this darn it).
Parcans are the cheepest theatre light and also the most durable. The original ones where nothing more than the headlight off a Volkwagon beetle (or similar car with a round headlight) put inside a can. The name is hence derived from the lens type (PARabolic reflector) and the fact that it is in a can. They are popular with rock shows since they take a lot of abuse inherent in transfer as opposed to the fragil fresnels and VERY fragile lekos. They are also easy to set up - just point and shoot. They lack any real controllability though - no shutters like the fresnel's and lekos, no lens adjustment, about the only thing they can take is a gel.
Both fresnels and parcans are divided up into their lens diameters - the bigger the lens the bigger the area they cover on stage.
Finally, Gel's are the colored plastic put in front of the light to give it a color. All the lights given above can take these.
Oh well, there's today's lesson in theatre
