From: nitram@tellabs.com (Marty Hewes)
Newsgroups: alt.3d
Subject: Re: 3d video?
Summary: Great Idea
Date: 3 Oct 92 03:39:47 GMT
Distribution: alt
Organization: Tellabs, Inc.

In article <1992Oct1.750.799@channel1>, "rafael ramirez" <rafael.ramirez@channel1.com> writes:
> sbooth@lonestar.utsa.edu (Simon E. Booth) wrote:
> 
> >This is purely hypothetical, but is a 3-D video camcorder possilbe with
> >exitsting technology??  I do amatuer video work and 3-D video is an interst
> >prospect for the future.
> 
> I'm about to try this:  ordered a (Pentax) beam-splitter, which takes
> two views at about the separation of the human eyes (65 mm) and "brings
> both views together" to be "fed" though the usual 35 mm camare lense
> (and that of my Hi-8 camcoder).  The recorded result, two side by side
> views, each taking 1/2 of the screen, sort-of "splitting" the screen
> vertically in two.

I've been contemplating the same.  I have a Sony 8mm and a Stitz beam 
splitter stereo attachment. 

> 
> Now, I hope to be able to one of the two:
> -Playback the stereo pair through my LCD video projector (hopefully)
> though the beam splitter, placing two opposited-polarised filters, one
> at each end of the splitter and projecting the image onto a metallic
> screen.  Viewing should (fingers cross) work by fitting the audience
> with appropiatedly polarized glasses.

Sounds like it might work, as long as the projector lens is relatively
small diameter (so the splitter doesn't vignette the corners) and the 
heat of projection doesn't harm anything.

> -Just use a "splitted-slides" viewer gadget (usually "supplied" with the
> beam splitter), but instead of a slide I will place a small hi-res
> (relatively speacking) LCD color television.  This method, besides being
> 1 person at the time only, losses in resolution and general enjoyment.

I believe all of the viewers of this type have magnifiers in them set to 
focus on the slide.  This would require the LCD screen to be flat against 
the viewer.  That, in turn, would require the LCD display to be the same 
size as a 35mm frame.  Is there one made that is only 24 x 36mm?

> Now, IF ANYONE would make and market an attachment that, when screwed on
> my video camera's lense would take two views separated adjustably
> between 6mm and 10mm (whisful thinking:), allow for small convergence
> setting (more whisful thinking:),

The Stitz adapter has more adjustability than the Pentax.  It is adjustable
for convergance, and the width of the dark band between the half frames, as 
I recall.  Unfortunately, the Stitz is no longer made.

> obtain the views from an anamorphic
> lense, so that "wide screen" shotting is possible, since we are going to
> loose half the width on the other view anyway (TONS of whisfull
> thinking), and then allow for playback+polarizing trick doing the
> reverse procedure with a LCD video-projector, what can I say? Here are
> my $1,500, now where can I get it?

The beamsplitters do not have a wide enough field of view to handle the 
anamorphic lens behind the splitter, but twin anamorphics in front of the
splitter may work.  I have a matched pair of anamorphic auxiliary lenses
I could try, but I think they are greater than 62mm diameter, so getting
them side by side in front of the splitter will be tough.

> 
> I'm going to contact a couple of houses that specialize in custom lense
> work for the movie industries.  See what the say.  If anybody has
> done this or has more info, PLEASE ..... (let me know)
> 
>  * SLMR 2.1a * Rafael.Ramirez@channel1.com from SPAIN! (A.K.A. RRC)
> --
> Channel 1 (R)   Cambridge, MA
> 

As far as viewing, I was just going to try watching the TV crosseyed.  I
have been playing Flight Simulater on the PC in 3d this way for a while.
It works pretty well, and is good eye exercise.  I don't think you'd 
ever get a whole room full of people to try it though.


Good luck, I'll post what I find out.

Marty.