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Projecting onto glass Answered

Alright here's my question, I know I've seen it done a couple places, the first image I could find as an example was just this :
http://www.en.dnp.dk/data/4418/3791/4418.jpg# (just see below)

What kind of glass do I need to do something like this? I'd like to build a table of sorts out of glass with a projector built into the frame under it to project upwards onto the glass, then eventually perhaps adding an IR sensor and work towards building a touchscreen/MS-Surface-like table. Any thoughts? Obviously its not normal glass or the projector would just pass through it



2 years ago

I'm not quite sure what effect you are trying to achieve but if you want to look down at the table and see an image then have you thought about sudo holographic images (IE not really a hologram at all but look a bit like it). Look up peppers ghost and see what I mean. So basically you'd have a projector under the table but at the side with it's axis horizontal. Then put a pieces of thin glass or plexy at 45 degrees to the projector then another piece of clear glass as the table top. Now you will see your image floating in the space under the table top. It works basically by using the angle of the glass to reflect some of the light. Hit glass straight on and the light will go through (nearly all of it) , hit it at 45 degrees and still some of it will go through and but a lot will will bounce of at 45 degrees (incident = reflection) thus 90 degrees from the origin. The reason you use a thin bit of glass at 45 degrees is that some light will get through the outer surface of the glass an hit the back surface and reflect and thus you may get two images not quite in line with each other and thus ghosting the edges.. Keep the inside of the table painted black to reduce reflection and keep the rest of you image black and the effects are pretty amazing.. A holograph table.....

Has anyone tried sandblasting a masked off area and then projecting onto it?

Hello guys, last months I had to project onto a glass surface for a university exam, so I put a little research on my blog and I'm actually trying to list all the possible methods. I just post down the link if you're interested
Link >> http://fluidforfun.blogspot.com/2008/02/projection-on-glass.html

Finally me and my group used a video retro-projected on a glossy paper layer (or acetate vinyl) on a plexiglass panel. Works quite good, and it's economic even if you can't get complete transparency.

What about sanding glass? Has anyone tried with it?

3M has a product line called Vikuiti for this. You can cut it into any shape and stick it on glass for projecting from behind. It is a little pricey, but the effect is amazing.


Or any idea if this would be easier with some kinda of plexiglass? It might be cheaper/more suitable for this project anyway since its lightweight, but I'm not sure if its possible with plexiglass, but then again I'm not sure hwo to do it with glass :(

Since the cost-effective way is to use a frosted surface, plexiglass may be the way to go - it shouldn't take much more than a light sanding to make the underside of the tabletop frosted enough to see the image.


A large sheet of tracing paper under the glass would definitely provide a suitable surface, as long as you don't want to see through the tabletop when the projector is off.

Someone I went to college with did a lot of projecting on glass. I don't remember exactly how she pulled it off. I think it was slightly frosted on the top side.

Oh... when they do it in store windows they use this stuff called "rose glass" or something like that. It has a special kind of one-way tinting and is very expensive.

. The glass may be lightly frosted. Just guessing.