Hey thanks for the detailed reply, that would be great if you could find out, I’d be much in your debt. I’m kind of hoping my lighting will be okay as I’ve already bought my osrams, I’m going for a spacing of 2cm from centre point to centre point between the LEDs, which (including 3cm on all sides for the angle of entry) gives me an array of 112 total (14x 8 IRLED series +1ohm R).

I’m trying to make my system as modular as possible, and spent ages on google sketchup trying to make the maths of an aluminium frame (but corner rather than enclosed frame) work with the thickness of my MDF layers. It was impossible without air gap and in the end I decided on a system of 8 LED series modular MDF blocks that can be individually connected to/dissconnected from the main (+/-) rings. Each block will be insulation tape skinned and silver foil faced on the endlighten/LED facing edge. The benefits are that I Can get the layers flush with each other, wire it up to my pc’s PSU to aviod uneccessary plugs and also replace individual components easily in the event of failure or breakage.

each block is an L-shape piece with a + and - end like this: 

1cm-IRLED-2cm-IRL-2-IRL-2-IRL-2-IRL-2-IRL-2-IRL-2-IRL-1cm
||-----------------------------------------------------------------||
||---------------------ignore dotted lines-----------------5W 1ohm C. Res
||-----------------------------------------------------------------||
to +12v ring--------------------------------------------------to - ring

I hope this is enough, perhaps I should double the total array LED quantity and halve all the spacing, making it equal to the ribbon’s? Would be pretty fiddly but do-able. I’d prefer to stick with soldering for the above reasons as well as the nasty cost of importing stuff to the UK (I paid £35 to UK customs ontop of the £40 delivery for peau’s custom cam, almost doubling the price).

Is there a reason for why the matrix has to go below the endlighten rather than ontop? I’m not keen on the idea of 8-10+mm space between finger and screen. Ideally I’d be looking for this layering:

anti-scratch-film covered thin (2 or 3mm) top layer
----------------------------------------------------------
LCD Matrix
----------------------------------------------------------
Endlighten XXL 10mm
----------------------------------------------------------
thin diffuser (perhaps 3mm one-sided plexiglas satinence or crystal ice, maybe even just skin the bottom of the endlighten with a diffuser film)
|
cab space = 50cm
|
ps3eye (i have the fisheye lens but should be able to compensate by overshooting the screen size, I also have FS mirror if necessary)
----------------------------------------------------------
original backlight

I was also wondering if instead of the original backlight, I could get an additional 8mm endlighten sheet, skin it with a translucent diffuser film of between 60 and 70% pass-thru, edge light it with vis spectrum LED’s at an appropriate wavelength (would I go up or down here to best fit my osrams and 880nm band pass filter?) and position it directly underneath the IR endlighten. If the ps3eye can see through the diffuser anyway and filter the light, couldn’t this work?

Sorry for the tirade of questions, but you’ve achieved the closest I’ve seen to what I’m after so I feel compelled to pick your brains.

Hey!
Took these screenshoots with 880nm and 850 filters. Different lens but that shouldnt make any differens in this test. As i can see the 880 and the 850 filter looks kind of the same when looking at the backlight. Kind of promising for your setup i guess.

Im sure the light will be enough. Just over do it, and you will be fine. The custom and shipment is terrible from the us, i know. I paid like 3 times more for shippment and custom than i did for the actual bp-filters at first.

About the layering, the lcdmatrix filters ofcourse some ir-light, like any other layer you put in your setup. This is why i have the matrix under the endlighten. I just get best blobs that way. And since i am a “build first and think about the problems later” kind of guy, i didnt forsee the cables from the lcd should go thru the setup when i built. Which i could, just once, think and draw some of my projects before i start building them but i guess thats just not me. My wife tends to do draw the interior once anyway.

On friday afternoon, driving home from work, i stoped and bought a plexi-sheet for some ftir testing. I might change for a ftir-setup, just meanwhile i am trying to solve the edge-problems of the dsi-setup. Still have half of the led-reel to play with!

Brilliant, thanks for taking the time to check that out.

I’m usually that kind of guy too, only this project seems to have spun out of control economically, a side effect of which being plenty of planning time between paydays. It’s a good thing too when I’m making dummy errors like adding 3cm instead of 6 to 2 dimensions to get 3cm on all sides. It also got me to try Google sketchup, which is pretty easy to use and it’s great to be able to problem solve 3D measurements before cutting anything.

I’ve taken apart an old TFT to build a prototype box, pretty sure I can fit it in functionally, just need to see if it lets the IR pass. Not sure if I should try and make 1 or 2cm spaced modules now though. 2cm modules would be a waste if they’re not good enough to be reused on the finished article, but I’m about 15 LEDs short of 1cm spacing and flat broke untill the end of Feb .

Thanks again for the help Limpa, I’d got it into my head that DSI wasn’t do-able with an LCD until I saw this and was about to fork out a hefty sum for an ultra short throw projector setup to get coffetable height.

hej limpa!
Very nice setup! Have you ever try with fiducials? It will be interesting to know if rearDI+LCD works with fiducials too

Thanks!
I havent tried fiducials at all but that was the very reason i chose the DSI setup in the first place. That and that i could use glass instead of plexi as surface. I have two young once that i want to use the table, as seen in my youtube-clip, and i think glass is better in the rough-handling-area.

I cant imagin running fiducials could be a problem with DSI-setups that are high enough and dont use fisheyelenses. Since i have trouble with the edges in my setup, also due to fisheye i think, i am now testing ftir. Have a new alu-frame with 10 mm plexi up for testing. The problem is that plexi scratches so easy and i have to use some kind of protectivfoil. Hopfully one that works as compliantlayer.
Personally i have no problem in makin fiducials with an ir-led and fibreoptics or maybe some reflective coats for my homeprojects. Although, my priority is to have a working table in my livingroom for me and my kids to play with.

Limpa - 08 February 2010 08:45 AM

Although, my priority is to have a working table in my livingroom for me and my kids to play with.

I’m into this so much! Hope you get it!

Yesterday i was trying to use fingers and fiducials with a rearDI setup (on pc-monitor-projector off) and i had success only if the fiducials where placed on the center of the acrylic. I know now (from your post) that 99% was the fisheye lens that didnt recognize the fiducials onthe edges of the acrylic. I used CCV 1.3 with fiducials.
I’m redirect to build a rearDI+LCD setup with 2 cameras. I think it’ll work like you said before.

Thanks for replying

Yeah, a solid 2 or 4 cam solution is the way to go for coffe-table-setups if you wanna play with fiducials i guess. I will ofcourse experiment with fiducialbuilds later on. Would be fun, for example, with a toycar that you could drive around on the virtual road and stuff happens along the way…

It would be nice to see that kind of game

Hey Limpa!

Something came in my mind now… what is the distance between PS3 camera and the plexiglass 8mm? And you use the plastic 0,1mm as diffuser for the backlight?
Thanks in adv