Hi, so I made a decently to-scale image of my planned box in 3dsmax the other day and I’m curious if anyone has any advice for it / do’s and don’ts. Right now the biggest questions on my mind would be the sandblasted glass, what IR emitters to use, and the cooling.
With the sandblasted glass, would it be a good surface to use and not lose any quality? Would the glass by itself be reflective enough too to hold in the IR light?
As for the emitters, I’m curious to know how many I’ll actually need. I’ve seen those great big 140LED ones and lots of smaller 28LED ones, whats better to use?
I’m also kinda worried about cooling since the box has to be almost completely contained and I know projectors can get really hot by themselves, so I want to make sure the box provides good cooling. So I thought of using 2 fans to circulate the air, but thinking about it now, I’m worried that it might dirty up the mirror and things with dust, which wouldn’t be too good. So where should I put those?
Hi, so I made a decently to-scale image of my planned box in 3dsmax the other day and I’m curious if anyone has any advice for it / do’s and don’ts. Right now the biggest questions on my mind would be the sandblasted glass, what IR emitters to use, and the cooling.
With the sandblasted glass, would it be a good surface to use and not lose any quality? Would the glass by itself be reflective enough too to hold in the IR light?
Not sure about the sandblasted glass. Depending on the intensity of your LED arrray the blobs may not show up. Someone else may have tried this and they know more but I think you’ll get a lot of reflected IR.
Edge - 05 July 2008 05:33 PM
As for the emitters, I’m curious to know how many I’ll actually need. I’ve seen those great big 140LED ones and lots of smaller 28LED ones, whats better to use?
My approach would be try a few arrays at first, test it out and work your way up to amount of LEDs that produces blobs.
Edge - 05 July 2008 05:33 PM
I’m also kinda worried about cooling since the box has to be almost completely contained and I know projectors can get really hot by themselves, so I want to make sure the box provides good cooling. So I thought of using 2 fans to circulate the air, but thinking about it now, I’m worried that it might dirty up the mirror and things with dust, which wouldn’t be too good. So where should I put those?
Thanks a lot for any feedback on my setup.
A small computer case cooling fan should do the trick. Mount it on one side and cut a hole on the other. Put filters cut from and AC filter pad on each one.
Sorry to say that your mirror setup as you have it will not reflect the image onto the glass. It will reflect off from the bottom mirror in the opposite direction from the projector, but at the same angle. Like a V. You’ll have to tilt the bottom mirror and then correct the image with the keystone adjustment on the projector.
Hey Edge, I used Sandblasted/Frosted glass in my setup. The frosted glass is 4mm thick, 71cm x 56cm. The only issue I have is that due to the sand-blasting there are tiny (and when I say tiny I am being VERY pedantic! ) reflective particles in the glass that make the projection sort of ‘glitter’ a little. (if that makes sense! And also i am about 3 inches away from the glass when I can see the effect).
As for IR reflection, in my setup it doesn’t seem to be a problem even with some of the IR Illuminators turned off. There is also no problem with hotspots from the projector too as the diffuser (frost) is on the underside of the glass.
Having said that, there are also films that you can buy like Purlfrost, so that you can bond it to an un-frosted sheet of glass that may not cause this effect (haven’t tried them)
1. You will need more IR because the glass will absorb a lot.
2. The frosting can greatly impact the quality of the projection, i had 4 pieces of glass...some more sandblasted than others. Each had varying quality of projection, some were too blury some were nice...I never quite figured out what the perfect setup was but it is possible to get good quality w/ glass.
Thanks everyone for all the feedback! Yes thanks for pointing out the mirrors, I’m sure I’ll be able to fix that, should be a good enough amount of space. I’ll probably only use fans on one side now.
Even more thanks on all the knowledge about frosted glass. I think frosted glass would have a very nice look and feel but it does sound like something hard to get done right. What other alternative’s could I do? I hear about Vellum, Rosco gray (not such good things on this one), Lee Filter, Tracing paper,and Mylar, which would you guys recommend for a DI setup like this? I would like to use glass as a hard surface on top if I could, Plexiglas works too I guess. I’m not to fond of Acrylic, especially when I don’t need it for a DI setup.
Thanks everyone for all the feedback! Yes thanks for pointing out the mirrors, I’m sure I’ll be able to fix that, should be a good enough amount of space. I’ll probably only use fans on one side now.
Even more thanks on all the knowledge about frosted glass. I think frosted glass would have a very nice look and feel but it does sound like something hard to get done right. What other alternative’s could I do? I hear about Vellum, Rosco gray (not such good things on this one), Lee Filter, Tracing paper,and Mylar, which would you guys recommend for a DI setup like this? I would like to use glass as a hard surface on top if I could, Plexiglas works too I guess. I’m not to fond of Acrylic, especially when I don’t need it for a DI setup.
with DI you could use glass on top, but again you have to deal with the glass absorbing IR. Once you get into multiple layers of surface you should think about keeping the distance between your finger and the projection surface low, the thicker the top material is the farther you will appear to be from “touching” the screen. Using some sort of projection surface with a 1/32 piece of plexi on top is one option.
I would worry about the bottom mirror getting dust on it from the air flow. Unless you use some sort of filter, witch will in turn make your fans work harder. I would plan for a tunnel or air duct that is in closed. Have it wrap around the box to the other side.
I would worry about the bottom mirror getting dust on it from the air flow. Unless you use some sort of filter, witch will in turn make your fans work harder. I would plan for a tunnel or air duct that is in closed. Have it wrap around the box to the other side.
I agree with this 100%, I am def experiencing this by blowing my fans across the mirror…
I am building a very similar DI setup. The enclosure seems to be a popular choice and I really liked the MS Surface table I played with a few days ago. In looking at the diagram though i was wondering if there is maybe a better position for the projector? I will be using an Optoma HD72. I plan on keeping the PC out of the box and connect it through an IO panel (speaking of which, does anyone know where I can either buy or get a custom panel made that parallel to the side of the box but inset slightly (think LCD monitors and how cables plug in parallel to the display, not perpendicular).
I’ve been using frosted window film with a very good results, I would recomend you to choose a very light frosted and test the results you have with one and two layers; right now I’m using a double layer setup for my DI unit, but about to try with Rosco Gray (as soon as it arrives).
At first, the larger IR illuminators seems to be the best choice, but they aren’t. I have try with a pair of 140 LED and the results are awful, the IR light is too focused, the high intensity beam just blind the camera, even the beam reflection at the glass (they work… but the performance is not the best); it’s really hard to find the right place to point the illuminators reflecting the IR upon very different materials and textures. For all this, the best choice always be to built a custom IR illumination setup. Try to built a couple of rails with LEDs at each inch or so, run some tests and you’ll see what you should do, more or less LEDs, longer or shorter distance, etc.
For your cooling system, I recomend to place both “extractor” fans at the very top of your box, that will ensure that you could blow the hot air out of the box and also cut a pair of windows at the bottom of the box but at the opposite side from the fans. That way you’ll be able to move all the contained air in the box. Always protect the ventilation holes with some kind of air filter; it could be any kind of fabric that allows air passing from it, but blocks dirt and any other unwanted items going inside.
One more thing, you are about to use mirrors at your setup, be sure to use FS mirrors, take a look around the forum, search for the different tutorials to make your own FS mirror super cheap.
