Indie beam-splitter stereoscopic camera rig designs

[John Pilgrim]

http://johnpilgrim.net/stereo3Drig/Rig-DownThrough-July5-v6b.jpg

http://johnpilgrim.net/stereo3Drig/rigIntro.html (http://johnpilgrim.net/stereo3Drig/rigIntro.html)

The link above shows some draft work-in-progress designs I have been developing this past week.

The objective is a high quality indie rig buildable for less than $1000.

Feedback is invited, but please remember this is a free open source project I'm sharing with the filmmaking community.

John
SF,CA

[Pedro Guimaraes]

reminds me of a homebuilt rig I saw, I think it was built by Tom Koester?

http://i232.photobucket.com/albums/ee298/ddragon76/s3d/DSC_7171.jpg

[Jason Goodman]

the problem with a sub $1,000 rig is going to be finding high quality glass in that price range. I actually do not think it would be possible. The aluminum parts could be cheap but quality optics are not likely to be. Also, it is hard to see from your CAD image, but is there a way to accurately adjust roll, pitch, yaw and height between the two cameras?

Jason Goodman
CEO
21st Century 3D New York
505 8th Avenue #1006
New York, NY 10018
212-244-8585

21st Century 3D Hollywood
3450 Cahuenga Blvd W #509
Los Angeles, CA 90068
323-799-1046

http://www.21c3d.com
jason@21stcentury3d.com

[Jeff Coatney]

I like where you're going with this, John. Jason, do you mean the glass for the beam splitter? Jason and Pedro, what type of glass does John need in his rig to make it viable?

[John Pilgrim]

My stereographer Drew Stephens found this place for mirrors: http://www.stereoscopicmirrors.com/

I'm curious from the high-end rig manufacturers what the specifications (parameters and values) are for the mirrors you order.

[John Pilgrim]

The current CAD file I posted has convergence (yaw) control.
I have mechanical prototypes for pitch and roll adjustment, that I haven't entered into the CAD file.
And at this point, it's all manual adjustment.

[Drew Stephens]

reminds me of a homebuilt rig I saw, I think it was built by Tom Koester?


Hey Pedro, I can confirm that rig is one of Tom Koester's DIY experiments, that he has graciously shared with many of us. He built that frame with "EZ Tube", using only a hacksaw and rubber mallet. I recall Tom saying that he had about $500 or less invested in that rig.

But check out some of the functionality: dial-in inter-axial (using the lead screw assembly on the upper camera); dial-in convergence (using another lead screw on the pivoting base camera); fine adjustments to the mirror (for trying to overcome pitch, yaw, roll inconsistencies). Stylistically? Well...I think that the curly angle brace for the mirror gives it a nice "wild west" flair. :thumbsup:

Seriously though, I'm hoping that we can take a lot of the great experiments that people like Tom have shared and "plus" them with information & craftsmanship that professionals like you all can offer, to make stereography more accessible and affordable for newbies (like me).

Thanks for your feedback & advice on John's drawings!

[Kwan Khan]

Nice Links

[Jason Goodman]

The glass we use in the 21st Century 3D BX3 beam splitter (http://www.21stcentury3d.com/news/) is custom designed for stereo cinematography. We have worked for several years with our optical engineer and various glass manufacturers and coating processes to develop the formula we think works best. We consider it a trade secret and other than saying it is expensive to have made and provides excellent balance between the reflected and transmitted images, I would probably say no more in a public forum. The mirror is also enhanced by a filtration process designed to handle linear polarized light and eliminate the artifacts seen in many stereoscopic beam splitters.


Jason Goodman
CEO
21st Century 3D New York
505 8th Avenue #1006
New York, NY 10018
212-244-8585

21st Century 3D Hollywood
3450 Cahuenga Blvd W #509
Los Angeles, CA 90068
323-799-1046

http://www.21c3d.com
jason@21stcentury3d.com

[Pedro Guimaraes]

The mirrors is definately where the magic happens or doesn't.

I'd just add that having a glimpse of the research and attention going on behind the scenes into optics on 3D rigs coupled with my insight into the post world afforded to my by my step-father. He is a quantel pablo 3D operator and has shown me deficiencies and issues with footage I have brought to him from several rigs...I can also attest to the fact that there can be a HUGE difference in the amount of post production time spent equalizing color, density, distortions and other aberrations (there's no fix for polarization issues) depending on which rig/glass the footage emanated from. It's really eye opening experience when you sit on a Pablo suite with a 20k monitor and a 100k christie 2k projector and a good colorist to show you before and after treatments and also comparisons of footage.

Like usual a few dollars spent in production (on a high quality rig/glass) can save tens of thousands of dollars in post in the pablo finishing suite.

Last I checked the average rate for pablo time was around $1000 and hour with an operator. So you can see how that can add up fast.


Now if your just looking to make some youtube anaglyph videos that's different. But if its for anything high dollar, well all of us know the math.

[Joey R.]

Mirror cost is only relevant because you are looking to get one or maybe a small handful. Mirror costs are based on economics of scale. When you buy 500-1000 units at a time, cost per unit becomes negligible quickly. Same is true with socks and condoms :P

[Jason Goodman]

Of course economy of scale will apply to anything in manufacturing. Given the choice I still prefer premium items in any of the suggested categories.

Jason Goodman
CEO
21st Century 3D New York
505 8th Avenue #1006
New York, NY 10018
212-244-8585

21st Century 3D Hollywood
3450 Cahuenga Blvd W #509
Los Angeles, CA 90068
323-799-1046

http://www.21c3d.com
jason@21stcentury3d.com

[Brian Petrie]

While it's not DIY cheap, these are affordable 3D rigs if you haven't already checked them out. However, I don't know anyone who's used one or how well they work. If anything, maybe it can help with your design.
http://www.3dfilmfactory.com/index.php?option=com_content&view=article&id=52&Itemid=76

[Riku Naskali]

Pedro,

Care to share your findings about mirror qualities on different rigs ;)?