Build your own Stereoscopic 3D Headset for pennies (part1)

Recently there has been a lot of interest in 3D stereoscopic headsets for gaming purposes. Michael Abrash has written some excellent posts on the subject and there were presentations at GDC.
The Oculus Rift is a kickstarter project to create awesome hardware for a 3D stereoscopic headset. Sony also recently released a 3D headset and I was lucky enough to try one for a couple of days.
But what can we do for under 50 bucks? How about a stereo viewer attachment for a smart phone.
One day I was playing with a PS Vita handheld gaming console and I realized it would fit into my Stereoscopic Postcard viewer. I downloaded some 3d postcards and viewed them in this manner and was not displeased with the results.
The OWL is absolutely the best postcard viewer out there but unfortunately unless you have a giant phone, the screen isn't big enough to cover the area the viewer requires. The images used on those old postcards was pretty big.
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The Oculus Rift is a kickstarter project to create awesome hardware for a 3D stereoscopic headset. Sony also recently released a 3D headset and I was lucky enough to try one for a couple of days.
But what can we do for under 50 bucks? How about a stereo viewer attachment for a smart phone.
One day I was playing with a PS Vita handheld gaming console and I realized it would fit into my Stereoscopic Postcard viewer. I downloaded some 3d postcards and viewed them in this manner and was not displeased with the results.
The OWL is absolutely the best postcard viewer out there but unfortunately unless you have a giant phone, the screen isn't big enough to cover the area the viewer requires. The images used on those old postcards was pretty big.
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A Smaller Format

I looked around to see what smaller formats had been used in the past for stereo and that lead me to the Stereo Realist format. This was a camera system that sold in quite large numbers between 1947 and 1971. It was based on the 35mm film format and so the viewer is compact enough to fit on the screen of most smart phones.
The viewers are readily available from http://www.3dstereo.com/viewmaster/svn-101.html for $3.50.
The viewers are readily available from http://www.3dstereo.com/viewmaster/svn-101.html for $3.50.
Modding the Viewer

The viewer as supplied looks like this. You would have placed the cardboard slide holder containing the images between the white and black plastic and held the white end up to a light source, its basically a simpler version of a View Master but the images are larger.
For our purposes all we need to do is remove that white piece. I pulled it off with pliers. It is glued on so be gentle when you do this. You don't want to damage the black part.
Once you've done that you simply use the viewer to look at your 3D image on your smartphone screen.
For our purposes all we need to do is remove that white piece. I pulled it off with pliers. It is glued on so be gentle when you do this. You don't want to damage the black part.
Once you've done that you simply use the viewer to look at your 3D image on your smartphone screen.
Building Test Assets

I searched around on the web and found some scans of Realist slides as well as the written specs. I then used these specs to position a set of antique postcard images into a .jpeg.
Note that I actually made the images larger than those used in the original system so they fill the area under the viewer effectively resulting in a wider field of view.
Then I loaded these into my phones picture viewer. I'm not sure if I got lucky or if the picture viewer preserves the size of images if it can, but everything lined up perfectly on the first attempt. Yaaayy 3D.
Note that I actually made the images larger than those used in the original system so they fill the area under the viewer effectively resulting in a wider field of view.
Then I loaded these into my phones picture viewer. I'm not sure if I got lucky or if the picture viewer preserves the size of images if it can, but everything lined up perfectly on the first attempt. Yaaayy 3D.
Does it work?

It works. It's not mind blowingly awesome, but what did you expect for under 4 bucks. :-)
- LCD Pixels are clearly visible
- 50mm is not a particularly wide angle lens. We waste a lot of the phones resolution because of this.
- The viewer is a bit shiny inside. I painted it internally with flat black hobby paint.
Next Step, making the actual headset.
Go on to part two to see how I actually built the headset