Gobos: More than just a character on Fraggle Rock

Many new event planners may hear a word used frequently that reminds them of early morning 80's cartoons and wonder "what the heck does a Fraggle named Gobo have to do with event lighting"?

A gobo is actually an excellent lighting tool used to create patterns, logos and other images using light. According to wikipedia the goofy name is actually an acroynm for "Goes Between Optics".

There are three main types of gobos which I see frequently used at events: Steel, Black & White Glass and Colored Glass.

Steel

I like to think of these as lighting "stencils". They mask off part of a light and only let it through in the shape of your image - much like a stencil does for paint. These are typically the most affordable type of gobo however they can only display one color at a time (usually provided by a color gel placed over the light along with the gobo) and solid blocks of color. You cannot add shading and small details can become blurred. Custom steel gobos are usually available for less than $100.

They can produce effects such as these when "colored" by a gel.

Black and White Glass

Glass gobos are custom fabricated and allow for grayscale, shading and finer detail. Black and white glass gobos can still only display one color if they are gelled.

Color Glass

These are the most versatile - and typically the most expensive type of gobos. The benefit is that they can display a multi-colored image, shading and even recreate photographic images (though the image won't be as clear as a digital projection). They can run as high as $500 each or more.

Gobos on their own are just a template. They don't work unless they are affixed to a special light source such as a Leko light.

There are a variety of sizes of gobos and lighting units so ensure you know what size your light requires before having a gobo produced. Typically gobos come in sizes such as A, B, C, D, E, G & M. I most commonly use A & B.

Make sure you have realistic expectations of where your gobo can be displayed. Flat surfaces work best and the light needs to be shone straight at the surface if you desire a distortion free projection (such as a logo). Therefore you need to make sure there is a good rigging point directly across from the surface you desire the gobo to be displayed on.

Abstract and natural patterns (such as leaves and clouds) are a little more forgiving since distortion doesn't ruin the image.

The space between the light and surface must be obstruction free of the light will be blocked and a shadow will break up your projection image. Also be careful that the gobo light won't be shining directly into guests' eyes since Leko lights tend to be VERY powerful.