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I use a 40 watt LED gobo projector to project light through a gobo. The "gobo" is a glass or metal disc with a maximum 40mm image. The other end of the projector is an adjustable lens for focus and size. I would like to project images captured from photos for everything from creating room textures to projecting images and logos for individuals and businesses onto walls and screens among other surfaces.

The metal and glass discs are expensive to have made so I search for a way to achieve the same effect with perhaps photo slide transparencies or film.

I need to get the digital photo onto an opaque substrate that can have light shined through it with zero bleed through except, of course, the image desired.

Any idea or suggestion on what the process and material would be?

  • How opaque do you require? Film is not opaque of course, so even very dark areas of developed slide film will still bleed some light. – scottbb Nov 1 '17 at 23:11
  • Completely opaque is the target for pure black areas of the gobo. – California Pro Sound And Light Nov 6 '17 at 17:25
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You might have some success with using a lithographic material such as Kodalith-ortho, Type 3. It was used for photomechanical reproductions and special effects for light shows back in the day.

It is high contrast and high density material. Density of 4.0 is normal. It can be screened for half-tone renditions. It has an ISO around 6.

The sheets are dimensionally stable 0.003" PET film base. I don't think glass plates are still available. If they are, a glass cutter can be used for making the gobo. If the film is okay; but, you need something flatter, maybe you could sandwich the film between two glass disks for the job.

Originally, gobos had to be made of metal because of the high temperatures of the light source. If your projector is LED driven, perhaps the temperatures are within the capabilities of these "slides."

The glass sandwich hi-con slides used to sit in an air-cooled projector for hours, day-after-day, for weeks, with no noticeable damage.

  • Hey Stan, your solution will be attempted if the "slides from digital" recommendation doesn't pan out. Thank you for taking the time to provide a path to success for me! – California Pro Sound And Light Nov 6 '17 at 17:25
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Their are numerous shops, you can search the web, digital file to slide (transparency). A quick search discovered http://www.slidesfromdigital.com/ Their are many others. My thought, a 40 watt projector is insufficient as photo transparences will likely need more wattage.

  • Thanks Alan - This looks easy and inexpensive. Thank you for helping to solve a problem I couldn't quite figure out. Side note; you would be surprised how bright a 40 way LED source is depending on projection size and distance from screen/wall etc. – California Pro Sound And Light Nov 6 '17 at 17:23
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I have a EZ Gobo machine and used http://www.slidesfromdigital.com many times. I didn't know what I was doing, but talking to them they were able to size my slides for me. Sometimes I submit a white background which they say do not do, but they can convert the white to a black background. The black background blocks out most of the light. In a low lit room you can't tell or see any light coming through the blacked out area.

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