What is a gobo?
GOBO is a special glass, metal or plastic (film) template. Steel gobos use a metal template from which the image is cut out of. These types of gobos are the most sturdy of the common gobo types but often require modifications to the original design called bridging in order to display correctly. In order to correctly represent the letter "O" for example, small tabs or bridges must be made in order to keep the metal tab in the middle of the letter supported. This effect may be undesirable in more intricate patterns or designs. Glass gobos are made from transparent glass with a partial mirror coating to block the light and produce "black" areas in the projected image. This eliminates any need for bridging, since the glass itself is the support, and allows more intricate images to be produced. Glass gobos can also include colored areas (much like stained glass windows), whether by multiple layers of dichroic glass (one for each color) glued on an aluminium or chrome coated black and white gobo, or by newer technologies that allow the thickness of the dichroic coating (and therefore the color) to be varied in a controlled way on a single piece of glass, making it possible to turn a color photo into a glass gobo. Glass gobos generally offer the highest image fidelity but are the most fragile. 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 without the delicate nature. These plastic "LED Only" gobos are new to the market, as are the lights they go in, so there is much about the durability and effectiveness that will vary from brand to brand.
Which light is best for projections?
In this case darkness is our friend. Daylight and sunlight are disruptable influences. To make light visible in light is comparable to trying to see white drops in a white colour. You need contrast. Shadow, dark areas or cloudy skies provide some clarity for images but the clearest are achieved in total darkness and these can be projected over far greater distances.
Artwork Quality for Glass Gobos
Vector Format: For line art designs or typical illustrations, we require vector format. Please convert text to outlines or vector art. This prevents possible problems with font substitutions and interpretations. The file format should preferably be: .eps (Encapsulated Postscript) .ai (Adobe Illustrator) For halftone, raster, gradients or photographic oriented designs, we require bitmap format. The file format should preferably be: .eps (Encapsulated Postscript) .psd (Photoshop) .tif .bmp jpg (uncompressed if possible) gif (uncompressed if possible) For professional art, please provide a minimum resolution of 600 dpi.
How the gobos are manufactured?
Glass gobos are made with the aid of digital templates and a high intensity three laser system. The data is transferred and etched onto specially coated heat resistant glass. Coloured glass gobos consist of several layers of dichroic coloured filters each one of which has been separately worked on by the laser before the multi layered gobo can be fitted together. An advantage of this method is that every copy of data is exactly reproduced with exceptional precise quality.
What surface is the best for projection?
The best surface is a white one because it reflects the light better. But light coloured surfaces, pink, yellow, light blues and greens etc. are also passable alternatives. Mirrors and stainless steel surfaces should be avoided because they reflect the whole of the light. Goods on display in cases, on shelves or in shop windows can also be good surfaces for projection.
How to handle and clean a gobo?
Our glass gobos are a quality product and offer the best optical image quality combined with high thermal protection of the greatest possible technical standards. It's necessary to read the following points carefully to ensure the durability and optimal performance of your gobos: Never touch the hot gobo when it's in use, (i.e. in a projector.) there's a danger of getting burnt! Avoid drastic temperature differences. Never put a cold gobo in a machine that's already reached its working temperature. The gobo could crack or break. The heat protection filter of the projector should be in perfect condition otherwise the gobo could be damaged because of overheating. Only use the size of gobo which has been recommended by the manufacturer of the projector. The clean, fat free and without fingerprints gobo should only be used in one of the recommended holders, (gobo holder, gobo wheel or gobo ring.) It should never be used in colour wheels or any other holder which hasn't been designed for the job. It's important to ensure that the gobo is placed in the holder precisely as one sided pressure can lead to tension and the glass breaking. When using ring shaped adapters of metal which are recommended by some manufacturers it's important to ensure that the gobo isn't skewed or slanted because that causes tension. If the gobo is mounted and fixed with silicon you should allow an hours drying time before using the machine. Any immediate heating of the silicon will lead to it releasing acetic acid which will damage the glass gobo. If it's in continuous use the glass gobo should be carefully cleaned every 2 – 4 weeks, (depending on the state of its environs,) to ensure optimal image projection. It's important to ensure the cooling system is in order to prevent damage to the machine and/or gobo due to undercooling.