3D Stereography Rig

overnighttolondon

overnighttolondon

Well-known member
Hey guys, just wondering if anyone's played around at all with stereography, i.e. shooting with two identical cameras close together and then tinting for use with those old red-cyan 3d glasses (or I guess not-so-old e.g. Spy Kids 3d, mars lander, etc)

I've done a bit of stuff with 3d animation so I can do the post side of things (let me know if you want more info on this), but I haven't experimented with mounts or rigs (how far apart? aligned with gears or something?...). Anyone tried this?
 
I visited ACE in prague, one of barrandov's computer fascilities, and they didn't use that at all, they used, **** i forget the term, but basically one eye would see one form of light, and the other, another.
 
Probably polarized projection. They project the two images polarized 90 degrees apart.

Or maybe LCD shutter glasses? Sync the shutters on the glasses to the images being shown.

Oh. Forgot. The two lenses should be about 3 inches apart. More or less.
 
my buddy was talking about this the other day. Said that he was experimenting by mounting two apple iSights on a board and recording simultaniously. I also remember him saying that he found a method where you wouldnt need colored glasses at all.
 
Yeah there are two methods of separating the eyes that I know of other than the colored glasses. As GenjerDan said, you can use polarized projection (this is the best method) or the shutter glasses, which work with interlaced signals on an CRT TV, showing you the lower field in one eye and upper field in the other (kinda strobey though)
 
The base (distance between cameras) is flexible. The wider you make it, the more of a giant you will feel like when viewing. And the more exagerated the depth will be. If you start with normal human eye base, you'll feel like a human when viewing, but not notice a lot of stereo effect. For distances greater than 30 feet (10 m) you may want to exagerate the base (more than 3 inches) to get more stereo effect.
For still shots you can just move a single camera sideways and take a second shot. For video, you need 2 cameras attached to a stereobar (just a mounting bar), and then move the stereobar. Later, you need to synch the videos.
I've used the www.reald.com Crystal Eyes alternating shutters, and also a different brand of polarized filters (like sunglasses - passive, like IMAX might use), the anaglyph (red/green) method, and mirror stereoscope which has 4 small first surface (silver on near-side) mirrors at 45 degrees to spread your eyebase out. \ \ / / so you can view side-by-side viewports. If you train your eyes to look straight ahead, you can see stereo with two side by side stereo images. www.christiedigital.com has some stereo capable projectors. In all cases, there are two viewports in some arrangement - side by side or up-down or on separate screens (for projected overlapping). You keep the cameras parallel except to maximize overlap you need to turn one camera in a bit - like looking crosseyed - and how much varies with your shooting distance.
I used all but the projectors in a field called photogrammetry.
 
I've been thinking of trying something like this using cheap cams. It's easy enough to mount them to a shoulder mount at the correct separation, but I'm not sure how to sync them up to be frame accurate. Would they need to be frame synchronized (ie. start recording frame 1 at the exact same instant) or would sliding them around in post get close enough?
 
jmc said:
I've been thinking of trying something like this using cheap cams. It's easy enough to mount them to a shoulder mount at the correct separation, but I'm not sure how to sync them up to be frame accurate. Would they need to be frame synchronized (ie. start recording frame 1 at the exact same instant) or would sliding them around in post get close enough?
Click to expand...

I did this a while ago with a couple of 8mm camcorders.
You don't need to be precisely frame-accurate for most stuff.
I was using a pair of sony handycams bolted to a aluminum bar.
I controlled them both with one infrared controller.
With those particular cameras, I got a slightly super stereo effect (inter-pupiliary distance greater than my own)
I guess with some of the new dinky consumer cameras, you could squeeze the IPD down to human-ish sizes.
In fact, this has got me thinking.... We have just got a load of new NV-GS180s at work for loaning out to students. I'll see if I can borrow a pair and report back.
 
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