Two steps forward

I swapped the floppy disk IR filter for a proper bandpass filter from peau productions and changed the lens for a wider angle lens. This means that the camera now points directly up at the LCD and isn't bounced off the mirror. A new lens mount meant improved focusing. I removed the fresnel from the LCD diffuser and that sorted out the ghosting. Lastly, even though is says it requires Leopard, the new version of CCV works fine on OSX Tiger and is a big improvement over the tbeta version I was using. I now think that I can get away without a compliant surface which would be excellent.

I've been thinking about how to get the whole unit to standby and start up quickly and simply as this will be important to usability. I think I've found just the thing, a one click intelliplug.

Blob sharpening

A wrapping of leather(ette) and a couple of coats of gloss have the box looking a bit more like a piece of furniture now.

Once I got it all together there were some problems with the blobs. They're not very bright and not tracking well. Experimenting in a darkened room revealed that the blobs were ghosted, so I guess a first surface mirror would have been a good idea.

Trying to improve the blobs, I ordered a bandpass filter to replace the floppy disk improv and that has gotten rid of the slightly grainy artifacts.

While I was at it, I also ordered one of their m12 lens mounts and it means the focusing can be more precise so I'm looking forward to seeing the overall results.

I've also picked up a fisheye lens to see if I can do away with the mirror. It broadens the field of view nicely.

The compliant surface was interesting. I hunted high and low for xylene and found nothing. Out of desperation I tried white spirit and it worked a treat. I'm now on my 4th attempt, using A1 sheets of acetate from Fred Aldous and silicone but the compliant surface hasn't so far given the leap in tracking quality I'm looking for. My G4 powerbook struggles with CPU and frame rate in tbeta, but that is going to have to wait.

The Box

I spent hours with Google Sketchup trying to model and plan the box dimensions and mirror placement. It's an excellent tool but I'm just not good enough with it and gave up on accurate blueprints.

I also spent hours brushing up on trig and trying to work out what the minimum depth I could get away with. Paper cutouts to scale were more helpful but in the end I decided to just put the mirror at 45deg. It's just a regular 4mm plate glass mirror fixed to a piece of chipboard with silicon sealant. Hopefully ghosting won't be an issue.



Wickes cut 18mm chipboard to size and all true & square. I used cabinet making corner blocks and wood glue to hold the thing together. Only after the first fit wasn't properly square did I think to use tie down straps around the outside to pull it all up tight whilst screwing & glueing.



The mirror supports and mirror are not yet fixed in place. A bit of experimenting with the camera show that there is only just enough space to allow the camera to see the whole of the LCD screen area in the mirror. I'm going to paint the interior in brilliant white to help produce a good diffused backlight.

LCD TV tear down

It's a goodmans GTVL32W8HD and has 2x SCART, 1x VGA, RGB and HDMI inputs




The LCD Panel is an LG Philips LC320W01










Taking it apart was slow but not complicated. There in the final pic you can see - left to right - the backlight, the controller boards and the LCD panel.

PS3 Eyecam

There are 2 kinds of PS3 Eyecams, you can read all about it at Peau Productions. I ordered one online and it was the difficult conversion kind. Despite being forewarned & my best efforts, I destroyed the lens. A fisheye lens from maplin was ordered because I want to keep the screen at coffee table height ( 16" - 18" ). The 3.6mm lens isn't a perfect fit, there's limited screw threads but just enough to come into focus. The floppy disk IR filter, tested with a TV remote control, works well in tests.

Shopping

Lot's of shopping, here are some links for suppliers, they've all been quick & good :
8mm Acrylic for FTIR
850nm IR LED strip x 5
PS3 webcam
Fisheye lens
and a 32" Goodmans LCD TV from ebay

1st post

Between the excellent lumenlab and nuigroup sites I decided I would have a go at building my very own multitouch coffee table.