Part 4 of a 4-part series on STAGE LIGHTING, which will be posted every other week.
(Tip: Even if you don’t have an extensive stage lighting system in your theatre, your vocational students will probably work with them in college or in the real world, so teaching these enlightening tips is always a good idea!)
There are many types of instruments that are used in stage lighting. Here are just three most popular types of ‘conventionals’ (not LEDs) and their uses. These are handy to have a sense of, because chances are, even if you have a full LED system, you may still have some conventionals hanging around that you may want to use for specific applications. They are:
ELLISPOIDAL/LEKO/”SOURCE FOUR”
These terms are used interchangeably. “Source Four” however, is actually a brand name, but these days it has become common for some people use it to describe this specific instrument. You can tell a person’s age by whether which term they use.
An ellipsoidal has, as its name suggests, an ellipsoidal shaped reflector with two focal points (yes – tech theatre does use math), plus two plano-convex lenses (flat on one side, rounded on the other side), along with a sliding barrel that allows the light beam to be focused with a hard edge (technically called a ‘hard focus’) and a soft/diffuse edge (technically called ‘fuzzy-wuzzy’). Because this instrument can be focused it can also house a metal or glass pattern that can be projected onto the stage. By substituting different barrels which have their lenses positioned differently, you can also change the angle of the light spread. The most common angles ellipsoidals come in is 19, 26, 36 and 50 degrees. There are wider and narrower available too. Ellipsoidals also have built in shutters that allow you to further control the light – for instance, if you just wanted to light a doorway you could shutter off all four sides so that no light spilled on the surrounding walls. Ellipsoidals are usually used for area lighting, sometimes for washes and for specials.
FRESNEL
Loosely pronounced “fer-nel”. You may have heard this term in connection with lighthouses. This instrument has the same fresnel lens that lighthouses do. This lens is ‘stepped’ and can therefore create an almost parallel beam of light – as used in lighthouses, and also in those annoying traffic lights that you can only see once you pull into that lane. In theatre though the lens is usually formed to create a nice evenly flooded spread of light. By moving the reflector and lamp closer or further away from the lens you can “flood” or “spot” the light spread. Unlike the ellipsoidal where you have to replace the barrel in order to change the beam angle, the fresnel has the capability to change the beam angle within the instrument. However, you give up the hard focus that the ellipsoidal allows. Fresnels are mostly used for washes and specials.
PAR
P.A.R. stands for ‘parabolic aluminized reflector’. A PAR has a reflector that is usually made of aluminum and is in the shape of a parabola. A PAR gives a fairly parallel beam, which can be adjusted by the use of different lenses. Also, because of the lens patterns, the light beam of a PAR is oval, not circular. This allows you to better control where the light goes, from an instrument that isn’t focusable. PARs are usually used as washes, sides and specials.
