Gobo Light Projector – Common Questions..

A gobo projector is actually a stencil or template placed inside or in front of a light source to regulate the shape of the emitted light. Lighting designers typically make use of them with stage lighting instruments to manipulate the shape of the light cast over a space or object-for instance to produce a pattern of leaves on the stage floor. Sources

The word “gobo” has come to sometimes refer to any device that produces patterns of light and shadow, and various items that go before an easy (for instance a gobo arm or gobo head). In theatrical lighting, however, the term specifically describes a device put into ‘the gate’ or on the ‘point of focus’ involving the source of light and the lenses (or any other optics). This placement is very important since it produces a crisp, sharp edged pattern or design (of logos, fine detail, architecture, etc.). Gobos placed following the optics usually do not generate a finely focused image, and therefore are more precisely called “flags” or “cucoloris” (“cookies”).

he exact derivation of gobo is unclear. It is cited by some lighting professionals as “goes before optics” or, more infrequently, “goes between optics”. A different explanation is “graphical optical black out.” The term is traced to the 1930s, and originated in reference to some screen or sheet of sound-absorbent material for shielding a microphone from sounds coming from a certain direction, without application to optics. The management of the term as being an acronym is recent and ignores the initial definition in support of popular invention. There are many online samples of acoustic gobos. The word probably is a derivative of “goes between.”

A custom gobo of the Earth, projected using a halogen projector. Gobos are used with projectors and simpler light sources to create lighting scenes in theatrical applications. Simple gobos, integrated into automated lighting systems, are popular at nightclubs along with other musical venues to produce moving shapes.Gobos could also be used for architectural lighting, plus in interior design, as with projecting a company logo on a wall.

Gobos are made of various materials. Common types include steel, glass, and plastic. Steel gobos or metal gobos use a metal template from where the image is eliminate. They are the most sturdy, but often require modifications for the original design-called bridging-to display correctly. To correctly represent the letter “O” for instance, requires small tabs or bridges to back up the opaque center of the letter. These could be visible inside the projected image, which can be undesirable in a few applications.

Glass gobos are made of clear glass with a partial mirror coating to bar the light and produce “black” areas in the projected image. This eliminates any need for bridging and accommodates more intricate images. Glass gobos may also include colored areas (much like stained glass windows), whether by multiple layers of dichroic glass (one for each and every color) glued on an aluminium or chrome coated monochrome gobo, or by newer technologies that vary the thickness of the dichroic coating (and thus colour) in a controlled way on a single piece of glass-which assists you to turn one photo into a glass gobo. Glass gobos generally provide the highest image fidelity, but are probably the most fragile. Glass gobos are generally made with laser ablation or photo etching.

Plastic gobos or Transparency gobos can be used in LED ellipsoidal spotlights. These “LED Only” plastic gobos can be full color (like a glass gobo), but are less delicate. They are new to the current market, as are LED lights, along with their durability and effectiveness vary between brands.

In the past, plastic gobos were generally customized when a pattern requires color and glass does not suffice. However, in a “traditional” (tungston-halogen) light fixture, the main focus point position of any gobo is extremely hot, so these thin plastic films require special cooling elements to avoid melting. A lapse within the cooling apparatus, for seconds, can ruin a plastic a gobo in a tungsten-halogen lighting instrument.

Patterns – Theatrical and photographic supply companies manufacture many basic and complex stock patterns. Additionally they can produce custom gobos from customer artwork. Generally, a lighting designer chooses a pattern coming from a manufacturer’s catalog. Because of the great number of gobos available, they can be described by number, not name. Lighting technicians may also hand cut custom gobos out of sheet metal stock, or perhaps aluminum pie tins.

Gobos are frequently used in weddings and corporate events. They can project company logos, the couple’s names, or virtually any artwork. Some companies can make wedding gobo in as little as a week. Designers rxziif use “stock” gobo patterns for these particular events-for example for projecting stars or leaves onto the ceiling.

The word “gobo” also is employed to describe black panels of different sizes or shapes placed from a light source and photographic subject (such as between sun light as well as a portrait model) to regulate the modeling effect from the existing light. This is the complete opposite of a photographer using a “reflector” to redirect light right into a shadow, which can be “additive” lighting and a lot frequently used. Usage of a gobo subtracts light from the portion of a general shaded subject and creates a contrast between one side from the face and the other. It allows the photographer to expose with wider open apertures giving soft natural transitions involving the sharp subject and unsharp background, called bokeh.