Ellipsoidal Reflector Spotlights, or lekos,
are the most flexible of the standard instruments in the theatrical lighting designer’s inventory.
When using the shutters on a leko, be aware that they function opposite to their placement.
When the physical bottom shutter is pushed in, the top of the light is brought in.
Using a leko gives you the option of using a gobo, also knows as a template or pattern. The gobo is
inserted near the conjugate focal point in a slot by the top shutter. This template will allow a
pattern of light to be projected. Many different patterns of gobos are available, and they can be
specially designed and ordered if necessary. In addition to a slot for patterns,
some modern units offer the option of inserting an iris unit. Similar to a camera’s aperture,
irises allow you to make the throw smaller in a circular shape as opposed to straight shutters.
This extra slot may also accept other special effects such as this FX tray. For this example,
I have a rain pattern that continually rotates in a never-ending loop. Other options available
include realistic clouds, water and fire. Be sure the effect loop is running before turning on the
light because of the lamps heat. The effect wheel typically requires an additional circuit of power,
and some can use DMX signal or voltage changes to affect speed. Other types of effects,
such as gobo rotators are also available. This extra-large slot also allows for the use
of a glass gobo – in this case created by small pieces of dichroic glass to create a stained
glass effect. Add an optional gobo to really complete the effect with just one light source.
The lenses on a leko are adjustable- this process of adjusting the lenses is called
‘running the barrel’. Running the barrel allows the light produced to have a sharp or soft edge.
If using a gobo, this will enable you to make the pattern crisp and clear, or fuzzy and diluted.
To produce an extremely sharp edge to the image or light, a donut may be inserted into
the gel frame area. A donut needs to be made of a heat-resistant material, not a flammable substance
like wood. The donut will eliminate the unfocused light, called highlation, and further clarify
the pattern. Realize that using a doughnut will cause some of the light’s intensity to be lost.
On the occasion where the front of the unit is being exposed to the audience,
you may wish to use a top hat. A top hat has a negligible effect on the thrown light of the unit,
but it will serve to hide the lenses, and the source of the light from the audience.
In addition it also reduces unwanted glare. Some modern units also allow you to rotate
the housing of the unit which permits more specific shutter cuts and gives the designer
more control over the projection of patterns thrown by the unit.
A selection of modern ellipsoidal reflector spotlights allow you to adjust the lenses in the
unit which effects the throw, or size of the light beam from the fixture. In this case, using an ETC
source four, I can quickly change the lens casing making a wider throw of 36 degrees, up from 19.