Sunday, June 20, 2010

3D Video on the Cheap

So the other day I was thinking about how 3D images are put together because we got a new 3D TV at work. It occurred to me that I had all the crap at home to build a small 3D video rig myself since over the last several years both of my daughters asked for and got some cheap Flip Video cameras. They're the original Flip Video camera, the 640x480 25fps ones.

I went to Pini's Hardware and picked up a few items to build a small stereo camera rig. It's comprised of a piece of cheap wood (a wooden garden stake), some half inch wooden dowel, some quarter inch furniture glides and some T-nut fasteners.

I assembled them like this:

It turns out the that "camera shoe" bolt is really just a standard 1/4" bolt and you can go to the hardware store and get a bolt that'll mount a camera anywhere.  It's not some special format like I thought maybe it was.

Here's what I bought at Pini's.  I got enough stuff to make two of these (or screw up one and make one good one, which is generally how I roll.)

Hit "Read More" to hear all about it and see some sample movies.

The build process was:

1. Measure everything and mark with pencil
2. Drill pilot holes for camera mounts
3. Drill slightly larger pilot holes on the bottom for the T-nut fasteners
4. Bang fasteners into place
5. Screw furniture glides into bottom of T-nuts.
6. Drill 1/2" dowel holes halfway through on top
7. Mount dowels
8. Drill screw pilot holes from bottom up through dowels
9. Glue and screw dowels into place.

I mounted the dowels as I did to allow me to hold onto the whole rig while simultaneously pressing the "record video" buttons with both thumbs.  In practice it works pretty well but even so, there's a small variance in start up times.

As you can see here, it's easy to reach the record buttons on the Flip Video cameras while holding the dowels.  Holding the camera rig with two hands helps keep it stable too.

The important part to get right is the lens spacing, which needs to be approximately 6.35 centimeters.  If you use the same model camera as I did, then just making sure to space the mounting holes at 6.35 centimeters does the trick:

And this project was cheap!  Not counting the cost of the cameras, It was under $5 to put this whole thing together.

Ignore the charcoal and lawn irrigation parts.

So that's the build.  Again, here's the end result with everything mounted:

So how does it work?  Surprisingly well, actually!

I shot some test videos yesterday and then took it out on a walk today.  The biggest issues are:

1. Lining up the shots in the frame.
2. Synchronizing the movies to start together.

Fortunately the software I'm using, Stereo Movie Maker, allows you to adjust horizontal, vertical, and timeline alignment to synchronize and align everything.

I've produced side-by-side 3D videos and red/cyan anaglyph videos.

The side-by-sides can be viewed in 3D by putting a stiff piece of cardboard between your eyes and the monitor running vertically between the two images to split the image down the middle.  If you relax your eyes until you see one image, it will appear in 3d.  You cannot cross your eyes to see these images in 3d, the images are in the wrong order for that.  I find that crossing eyes to view 3d images causes me instant headache and the images look blurry so I didn't even try to compose the movies that way.

The Red/Cyan Anaglyph images require red/cyan glasses like you'd get with some DVD promotions.  There are several different color separation techniques for viewing 3D images.  Red/Cyan, Red/Blue, Red/Green, Yellow/Purple.  I chose Red/Cyan because it's the most common.

Click on an image to download the full movie to your computer.

You can view them on your monitor, but may need to resize the movie so that your eye-to-screen distance is large enough to allow proper convergence of the two image (if you're using the cardboard card method of viewing described above.)

Let me know how they work for you.  And those of you with red/cyan glasses, please try those out.  I don't have any anaglyph glasses yet and am currently trying to track some down.

1 comment:

maik said...

Hi Steve!

I mention your Brushduino project in my upcoming Arduino book and I have a question.

I could not find your e-mail address, so I am leaving a comment here.

Please, e-mail me at:

contact 'at' maik-schmidt 'dot' de