This is topic Digital Technology for 3D?? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Mike Bianchi (Member # 271) on 06-08-2001, 10:52 PM:
Not to sound like I favor digital presentation over film (because I certainly do NOT), but I also love 3D and with the help of Tim Reed and the Condon family at Stereovision we've very successfully shown 3D films. Now I'm wondering if digital technology might be tapped for 3D projection.I'm hoping some of you true tech guys here would have some insight on a hair-brained scheme of mine. It may be off the wall, but such musings are often the nexus of technological advances. So what the heck?
So here's my cockamamie scheme...
Connect a digital source (DVD player?) to a projection source (Proxima type projector?) in conjuntion with a silver screen of course. The DVD would contain both the side-by-side or over/under images of a 3D film. Then the projector would be outfitted with a polarized mirror box.
Fire it up and set the convergence and...
... 3D, right?
There is probably some technological hurdle but this epiphany hit me the other day and I finally drew up the cajones to ask.
And the peanut gallery says...
Posted by Joe Redifer (Member # 3) on 06-08-2001, 11:09 PM:
The thing I HATE about 3D is that you always must wear some sort of eyewear. Annoying. I used to draw 3D comic strips by hand, and the effect was very convincing. But I noticed the readers would bitch about having to wear the glasses. I decided that the effect was not worth it.
Posted by Adam Martin (Member # 641) on 06-09-2001, 12:14 AM:
My customers are disappointed when they don't get to wear the cool glasses!I don't see why you couldn't do polarized 3D video projection ... as long as it was "filmed" in 3D.
You'd get a better result using two separate projectors (left eye; right eye) so that you get a better resolution and brightness. Don't forget the silver screen!
How would the video "lines" affect the polarization? Would you have to use 45-degree polarizers?
Posted by Joe Redifer (Member # 3) on 06-09-2001, 01:44 AM:
Adam, your post seems to insinuate that you are showing 3D without glasses. How could you do 3D without glasses (other than using holograms)? How will you tell the left image to go only into the left eye and vice-versa? There is nothing in the eyeball that says "I am the right eyeball, I will not allow certain images to pass that the left eyeball would." 
Posted by Mike Bianchi (Member # 271) on 06-09-2001, 02:29 AM:
The only problem with 2 projectors would by synchronization. That might be a solution if you wanted a large picture size, but I'm thinking more along the lines of home use or small auditorium.I don't mind the glasses - I have a nice pair with regular hard plastic lenses that are just like regular glasses.
The resolution lines vs. the lines of polarization are indeed one of those technical issues I hadn't thought of...
Keep 'em coming...
Posted by Adam Martin (Member # 641) on 06-09-2001, 11:08 AM:
We have special shows where we attach electrodes to the customers heads that are, in turn, attached to the shutter of the 3D projector. The electrical pulses cause the eyelids to open and close 48 times a second with the appropriate image on the screen. 
Really, though, I was talking about 2D shows.
2-projector synchronization could be done with the DVD timecode. Now, coming up with a way to modify the DVD players with a "timecode in" like on a DAT player ...
Posted by Gordon McLeod (Member # 33) on 06-09-2001, 11:24 AM:
We did a 3d presentation with to JVC Huges machine using timecode lock on the high8 tapes
Posted by Jerry Chase (Member # 660) on 06-09-2001, 11:30 AM:
Two projector digital 3-D on movie size screens has already been done. Millenium Theatre in Kissimme Fl, just down from Disney in the building that used to house "American Gladiators" did this back in 1998. They used two Barcos with a proprietary software program that turned 2-D high end video tapes into 3-D. This was actually the first place I saw true digital cinema using the TI chips. They were showing "Lost in Space" at the time I installed my ticketing software for them. The film worked well with their 3-D video software because of the large amount of panning in the film, which cued the software for depth. The effect was surprisingly good, with a very bright, clear, large picture.I'm trying to remember if there was an issue with the light coming out of the digital projectors being already polarized in some way. There might hae been or I might e confusing it with something else. Anyway, they had free standing polarizing filters in front of the units, and the throw was probably 150 feet or more.
The "theatre" was never able to make money, there is a long story about environmental impact fees, seating and restaurant business.
It was one of those ephemeral projects that you have to be in the right place at the right time to witness.
LCD shutter glasses are generally preferred for video based 3-D. The interlacing in the NTSC signal has been convenient for that.
Posted by John Pytlak (Member # 331) on 06-10-2001, 06:57 AM:
The pre-show for the 3D IMAX dome ride-film "Race for Atlantis" is done with 3D video. Seemed pretty good on a smallish screen, but the film presentation blew it away. Likewise, the 5-perf 70mm 2-strip 3D for films like "Captain EO" or "Honey I Shrunk the Audience" or the Universal Studios "Terminator 3D" attraction are very impressive. But everything pales when compared to IMAX 3D.The 3D presentation I was most impressed with was "Echoes of the Sun", done with IMAX "Solido" on a dome --- the 3D images literally surrounded you:
http://www.imax.com/films/distribution/echoes_of_sun.html
------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion
Posted by John Anastasio (Member # 607) on 06-10-2001, 07:18 AM:
There was a video game marketed quite a number of years ago that made use of field switching, showing one image per field with LCD shutter glasses plugged into the unit. People ended up with too many headaches. Perhaps you remember the system used in the Super Bowl about ten years ago which relies on the fact that your eyes respond differently to various levels of light. You had to wear a pair of glasses in which one lense was clear and the other dark. As long as the picture was being panned, you saw the depth information between the two eyes. Using polarized lenses in front of video projectors wouldn't be affected by the scan lines of the picture raster, since the lines aren't actually polarized...they're just long,thin picture segments. In other words, 3-D TV is nothing new. Shutter glasses, polarized lenses, anaglyph (2-color) 3-d has all been tried with varying degrees of success before. What's needed is a new type of display. The military is currently working with a clear crystal display which utilizes two intersecting ultraviolet laser beams. The crystal only flouresces at the intersection of the beams, so you can do a real three dimensional display (think of radar displays here). It was discovered by a young woman who was working on her graduate thesis. The problem is that the size of the crystal is limited and you only get one color. Of course, TV started that way too.
Posted by Joe Redifer (Member # 3) on 06-10-2001, 05:45 PM:
John-Have you seen the old Sega Master System videogame system that existed in the 80's? It had 3D videogames using LCD shutter goggles. I bet IMAX 3D couldn't touch that!