[Chimera-users] Fwd: Re: 3D stereo

Nadir.Mrabet at medecine.uhp-nancy.fr Nadir.Mrabet at medecine.uhp-nancy.fr
Sat Nov 20 05:28:10 PST 2010

Hi Matt,

Thanks for your input.

First, I should correct my ealier statement: DepthQ sells Christie's products
but does not manufacture them.

>From your mail, I understand that 30 people is the largest audience you can pack
using the 3D with DepthQ, otherwise correct me please.
Active stereo glasses 'Xpand' cost around $100, now, but battery replacement can
indeed become costly over time.

What sort of tricks have you been able to collect over your 15+ years experience
to implement stereo correctly.

I hear elsewhere that the ViewSonic DLP beamer (~$1400) might be a better option
and that it is worthless spending more money.

GREG- I also need your input.



Pr. Nadir T. Mrabet
Structural & Molecular Biochemistry
UHP - Nancy 1, School of Medicine
54505 Vandoeuvre-les-Nancy Cedex
Tel : +33 (0)
Fax : +33 (0)
E-mail : Nadir.Mrabet at medecine.uhp-nancy.fr

Selon "Dougherty, Matthew T" <matthewd at bcm.edu>:

> Hi Nadir,
> We have a early DepthQ.  The screen is about  ~three  meters wide, which is
> limited by the height of the room.  I would suspect we could go bigger.  We
> can pack 30 people in our conference room.  We have been doing stereo for 15+
> years.  The limiting factor we have seen is the cost of stereo glasses,
> originally $1k each & now at $300.  If you are going beyond 5 people a
> polarizer with passive polarized glasses is the way to go.  Unlike the Zalman
> and other monitors where you loose 50% of your vertical resolution, the
> DepthQ will give you full resolution because it buffers the LR frames.
> The big problem we have seen with stereo is implementing it correctly.  Just
> like color blindness, a fairly large percentage of the population just does
> not get it or barely gets it; but unlike colorblindness tests which most
> people are familiar with the concept and their personal results, stereoscopic
> vision ability is not normally measured or discussed, so most people are
> clueless about their ability or inability.  Optometry stereo tests are
> available and not difficult to use, they require no batteries or equipment.
> Beyond this, actually producing stereo imagery has some tricky hurdles.
> Stereoscopic effect is a macular phenomena, which occurs at the center of
> vision about the size of a baseball at arms length or the moon on the
> horizon.  In the real world the stereo zone is constantly moving as we move
> the focus of attention.  For one or two people exploring a dataset on a
> monitor, making these adjustments can be done (but could be significantly
> improved through better interfaces to stereo control parameters, like a knob
> on binoculars).  But for a large crowd, this interactive ambiguity can be a
> major liability, consequently a choreographed animation is needed.
> GREG- correct me if I am wrong here: using reset to change from keyframes
> does not change the stereo values, so this is a tricky problem in getting the
> stereo to change during the animation.
> Consider this, in the movie Avatar the stereo effect is weak and strong,
> depending on the focus of the storyline.  Through out the movie, there is
> stereo, no stereo, strong stereo, weak stereo, no stereo, etc.  The common
> problem in presenting to conference room crowds is the mistake of turning on
> the stereo, setting the parameters once and you are done.  To make it work
> effectively you have to dynamically change those parameters in a way that
> guides the audience to what is being revealed.  One size does not work, you
> have to make it work for the people in the front of room optimally, then
> adjust the effect for people in the back of the room to see it optimally.  It
> is the dynamically changes in the brain that accentuates the effect; too fast
> and you confuse the audience, too slow and they are bored.
> Matt
> ________________________________________
> From: chimera-users-bounces at cgl.ucsf.edu [chimera-users-bounces at cgl.ucsf.edu]
> On Behalf Of Nadir T. Mrabet [Nadir.Mrabet at medecine.uhp-nancy.fr]
> Sent: Friday, November 19, 2010 11:14 AM
> To: Greg Couch
> Cc: chimera-users at cgl.ucsf.edu BB
> Subject: Re: [Chimera-users] Fwd: Re:  3D stereo
> Hi Greg,
> Both DepthQ and Christie (made in fact by the same manufacturer.
> http://www.depthq.com/projector.html; http://www.depthq.com/christie.html)
> are, as expected, sold in France by a unique firm.
> They say that DepthQ HDs3D-1 ($2,995) has no capability for 3D for a
> conference room with 30-50 people, and that my only option is Christie (>
> $65,000!).
> Your earlier mail states that DepthQ can go along with a 3-meter size screen,
> suggesting it could accommodate an audience of 30-50 people.
> Can you, please, comment on all these issues and eventually let me know if I
> can go along with DepthQ DLP?
> Many thanks in advance.
> Best,
> Nadir
> Pr. Nadir T. Mrabet
> Structural & Molecular Biochemistry
> Nutrigenex - INSERM U-954
> Nancy University, School of Medicine
> 9, Avenue de la Foret de Haye, BP 184
> 54505 Vandoeuvre-les-Nancy Cedex
> France
> Phone: +33 (0)
> Fax:   +33 (0)
> E-mail: Nadir.Mrabet <at> medecine.uhp-nancy.fr
> Cell.: +33 (0)
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> On 28/09/2010 12:59, Greg Couch wrote:
> Subject:        Re: [Chimera-users] 3D stereo
> Date:   Tue, 28 Sep 2010 12:59:13 -0700
> From:   Greg Couch <gregc at cgl.ucsf.edu><mailto:gregc at cgl.ucsf.edu>
> To:
> Nadir.Mrabet at medecine.uhp-nancy.fr<mailto:Nadir.Mrabet at medecine.uhp-nancy.fr>
> CC:     Chimera-users at cgl.ucsf.edu<mailto:Chimera-users at cgl.ucsf.edu>
>  On 07/21/2010 07:24 AM, Nadir T. Mrabet wrote:
> > Hi,
> >
> > This is for teaching purposes so that students can "walk" though 3D
> structures. Would it be possible to use Chimera via a 3D stereo beamer to
> project display on a very large screen and watch the selected structure in 3D
> by means of shutter glasses?  If this is so, what kind of equipment would you
> recommend?
> >
> > Many thanks,
> >
> > Nadir
> So there were some developments at SIGGRAPH, but nothing that would
> change the previous recommendations made in the chimera-users mailing list.
> To summarize, for a large group of people, you want a setup similar to
> what is done for 3D movies in a movie theater, which is to use left-hand
> and right-hand circularly polarized light for the left-eye and right-eye
> images.  There are three parts to the setup: (1) projecting the stereo
> images, (2) reflecting the images, (3) receiving the images at the eyes.
> 1. For projecting the stereo images with chimera, you need a
> workstation-class graphics card, either an AMD FirePro (or ATI FireGL)
> or a NVIDIA Quadro (or Quadro FX, not Quadro NVS), and either (a) two
> projectors with passive polarizers, or (b) a single projector with an
> active polarizers.  The single projector method is much simpler to
> maintain because you don't have to keep aligning the two projectors, but
> may cost more because the projector has to be able to display at 120Hz
> (and there's the cost of the active polarizer).  The relative costs of
> the two options vary.  Active polarizers are available from DepthQ,
> http://www.depthq.com/, and RealD,
> http://www.reald.com/Content/professional.aspx.  DepthQ also sells a 3D
> projector that can display 3 meter wide images, and has European
> distributers, so that might be the best choice.  If you want a larger
> image, you'll need a Christie Mirage or a Barco projector.
> 2. To reflect the stereo images, you need a screen that doesn't change
> the polarization of the light.  There are lots of choices.  Google for
> "3D projection screen" to see what's available.  What screen you want
> depends on the layout of the room that the stereo projection will be
> in.  Narrow rooms can use screens with a smaller viewing cone and higher
> gain.  I've heard good things about Stewart Filmscreen, but get
> recommendations from whoever you buy your projector too.
> 3. Last part of making sure each eye only receives the image it is
> supposed to is for the person to wear circularly polarized glasses.
> Google for "polarized 3d glasses" to see what's available.  I'd avoid
> the disposable paper ones.  I like the RealD glasses that the movie
> theaters use.  Perhaps a theater would sell some to you.  The glasses
> from Zalman displays work too.
>     Bon chance,
>     Greg

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