Wide-eyed Wonder: an artist's musings on three-dimensional vision

Some are color blind. I am stereo blind.

Archive for the ‘optic flow’ Category

Stereo Vision Survey

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Exciting news! Bruce Bridgeman, the gentleman who gained stereo vision after watching Hugo, has teamed up with Sue Barry of Fixing My Gaze to create a long crowd-sourced research project in search of those who have experienced increased stereo vision after watching 3D movies.

Although my stereo experiences are limited and have not yet been scientifically verified, there seems to be room for even me to take this survey, as there is a comment section at the end of three different sections where I can plug in additional information. (In my case, how BRAO has affected my vision.)

I encourage all strabismic adults to at least read the survey, which is instructive in itself. If you have had a stereoscopic experience after watching a 3D movie, share your experience in the survey.

The survey also takes into account if you have had any vision therapy or had your stereo-awareness measured by a professional.

The VisionHelp Blog

If either you, a family member, or any patients you encounter have developed stereo vision as an adult – even intermittent or weak stereo vision – please complete this survey developed by Sue Barry and Bruce Bridgeman:



The survey and its background were just published on page 13 of the new journal, Vision Development & Rehabilitation.  Through crowdsourcing of this nature, Drs. Barry and Bridgeman may be able to provide evidence to support that the viewing of stereoscopic 3D movies and similar modalities can be therapeutic for certain individuals.  We blogged about that possibility here last year, and this survey is an important step in that direction.

Completing the survey is entirely voluntary. You do not need to answer every question before submitting it. Your answers are sent to a spreadsheet which simply tabulates your answers with no other identifying information.  Thank you in advance!

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Life of 3.1415926535 8979323846 2643383279 etc.

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… that would be Pi

I’d read so much about the artistic use of 3D technology in Ang Lee’s film Life of Pi, I decided it was worth a strabismic test. If I did not see palpable space, with things jumping off the screen towards me, at least I would see art: imagery that would move me and delight my eyes and heart.

I learned something even before seeing the movie: I’m probably the last person on the planet to arrive at a 3D movie only to discover the theater is playing a 2D version! I’d read so much about the artful use of 3D by Ang Lee, that I completely ruled out anyone wanting to see the movie any other way. And so our first trip to the nearest theater in the next town was self-defeating. We went grocery shopping instead.

But, almost two weeks later, Pi resurfaced (with the necessary “3D” listed in the title) in the next town over. (I had given up on Pi and was looking for the Hobbit. But Middle Earth can wait.)

It was good timing for taking in a matinee today, as I had exactly one week to adjust to my new bi-focal lenses with base-right prism (but that’s another story.)

As the film began, the hummingbirds in flight brought an audible thrill to the folks to my left. Ah, but they were too quick for me! And then a short conversation began between my husband and I: “Did you see that? says he. “No” says I. After a few more similar exchanges I said “If I see something, I’ll squeeze your hand.” I believe he got one hesitant squeeze as the monkeys rushed through the trees.

Then I forgot all about how I was seeing as I became immersed in the story.

It was a delightful story with visible layers of foreground, middle-ground and background all moving on their own planes, however if only within the screen for me. More delightful were the even more layers of meaning. Naturally it is easier to take the layers of meaning with me, and enjoy them in my mind long after the visual effects fade away. Ang Lee was masterful in using the concrete layers of the story to enhance the abstract and philosophical.

I had popped sinus medication and ginger pills before the trip, and the seas did get rough! But my stomach did not once drop out from under me. (Suppression has it’s advantages.) I also did not turn green around the gills when the seas turned calm with endless random bobbing. No ginger pills needed, unlike the many times I’ve been becalmed on Lake Erie in my father’s sailboat!

But the “float” stayed with me after the movie.

When everything is floating for two and a half hours, my guess is it does open one’s brain to recognize “float” in the real world.
Dr. Susan Barry describes her experience with “float”, saying “Knowing that objects are separated by volumes of space and perceiving those empty volumes are very different experiences. ”

My first thing to pop out toward me was not the whale in the movie, but my coat, hanging in front of me on a hook in the bathroom stall. It billowed towards me. (My first “sighting” since getting the new lenses.) The bathroom sink faucet took on the familiar forward projection, and doorways and all things moving in my periphery as I walked through the lobby swam in kinetic motion-parallax. A trip to Lowe’s afterwards revealed noticeable depth in the layers of paint chip racks. Empty racks of all sorts reached out toward me, and a small stand of Ohio State banners swam towards me as I walked by, like a school of fish.

I’m floating still.

Links to layers of meaning
Life of Pi: A Novel by Yann Martel By Phoebe Kate Foster http://www.popmatters.com/pm/review/life-of-pi/

‘Life of Pi’ Ending Explained by Ben Kendrick http://screenrant.com/life-of-pi-movie-ending-spoilers/

Links to layers of 3D
Life Of Pi’s Visual Effects Are Extraordinary. Here’s Why by Brendon Connelly

How did they bring the ‘unfilmable’ Life of Pi to our screens? by Nick Clark

Ang Lee On The Filmmaking Journey Of “Life of Pi” By: Scott Pierce

3D Movies and Stereoblindess

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Hi, I’m just curious … I don’t see 3D. Would it be possible for me to get a glimpse of your 3D movie and find out what I can see?

I asked this only after purchasing tickets for the 2D version of Narnia: The Voyage of the Dawntreader Afterward, I and my friends shared a pair of glasses to briefly check out the 3D difference.

Even though I didn’t get the “Wow!” of an object jumping off the screen or moving behind the screen that my friends saw, I would still pay the extra bit to see the richness of detail the new polarized glasses create. Everything was clear, and not a blur (which happened often in the 2d version. Thoughts on why later.)

With polarization, which cuts out some glare, I saw deeper colors. [1] I studied the golden shell Edmund pulled from the pool of gold, and it appeared richer to me, even though it was not 3D. Instead, it was similar to what I experience when I see a painting by that rare artist that can translate 3D to a canvas, such as my friend and portrait artist Judith Carducci.

Unlike legacy 3d movies that required the red-cyan glasses, the new technology uses a different kind of fusion. Legacy film 3D required two projectors running film perfectly in synch, shot with cameras that had to be aligned according to a precise geometric formula during filming. [2] One camera filmed through a cyan filter, and the other filmed through a red filter. The red-cyan glasses worn by viewers would cancel out the conflicting image and the binocular function in the brain’s visual cortex would fuse the two images from each eye to create 3D. [3] It was an imprecise method and never caught on, as every imperfection would create literal headaches.

Furthermore, the stereoblind, who could not bring the non-conflicting images together with one-eyed viewing, experienced a movie that was either completely red or cyan!

The new technologies are digital. No film is used. The two cameras that do the “filming” to digital files are precisely aligned with a computer. [4] Digital post processing of CGI effects is also rendered with 3D formulas. (In the case of Dawn Treader, only the post processing was 3D. Two cameras were not used to shoot the live action. [5]) The left and right integrated “film” file is shown through only one projector, as the input from both angles is digitally fused into one movie. [4]

Both RealD and Dolby 3D projection systems use a rotating high-speed alternating filter. Left and right images alternate so quickly that the brain takes them in through the Dolby optically coated or RealD polarized glasses as one continuous image. The coatings or polarization in the glasses cancel out the conflicting alternate images in each lens. [6] [7]

What this means for the steroblind is only every other image is seen through either the right lens or the left. There is no haloing or ghosting because the opposite image is blocked by the same lens the dominant eye is using.

This is good news! No ghosting! No red or cyan viewing!

Eye problems, even with the 2D version

The newer 3D movies rely on extraordinary optical flow and motion parallax. The rapid CGI rotation and camera panning appeared blurred or jerky to me in the 2D version, annoyingly so, because all my depth cues were put on steroids. It was like watching a home video where the would-be videographer didn’t know how to pan his camera. If these scenes had lasted any length of time, I would have needed to avert my eyes to avoid nausea, a common problem I experience due to lack of stereoscopic ability.

All of the film’s CGI sequences appeared jerky, like watching a video with a slow internet connection. At the end of the film, during the credits, the background had a very annoying flicker. I wonder if this is because the producer did not bother to create alternate 2D CGI? The film underwent 8 months of 3D post processing. [5] Making alternate 2D CGI sequences may not have been in the budget, especially if the producers thought the 3D ghosting or haloing and alternating flicker would not be noticeable to most viewers.

Secondly, much of the film was was shot with a lack of depth of field, especially during the layered action scenes onboard the ship. Because I am steroblind, relative size relationships and perspective behind and before the action were out of focus. I felt somewhat lost and annoyed without these depth cues, as I was constantly subconsciously attempting to bring the whole scene into focus.

In this image, Lucy’s face is in focus, but the painting and Edmund are not. This is due to the way the scene was shot, with a lack of depth of field.

All this points to a dim future for the stereoblind movie-goer, as every 2D version of a 3D movie is not going to be as easy to watch as the simple 2D movies of old.

RealD polarized or Dolby coated glasses would cancel out any 3D flicker that may be embedded in a 2D version, but how to find out if 3D sequences are in the movie? Would the ticket person be able to hand out the glasses for 2D movies if asked? Probably not. Better to spend the extra 3 bucks and just watch the 3D version with the same flatness I see in real life.

At least I am improving my peripheral awareness to enjoy the pumped-up optic flow and motion parallax that these new films are dishing out.

Links to the technology of 3d movies for further exploration

Popular Mechanics “The Tech Behind 3D’s Big Revival” April 2009 http://popularmechanics.com

“JDSU Shares Science Behind 3D” http://www.youtube.com JDSU is the company that developed the coatings for Dolby 3D. The commentator offers some lame misinformation, as his competitor’s polarized glasses are being recycled at movie theaters and not thrown into landfills.

“To 3D Or Not To 3D: Buy The Right Chronicles Of Narnia Ticket” http://www.cinemablend.com offers a sub-par 3D analysis of the film, as the reviewer says at one point that it didn’t matter if she saw the film with the polarized glasses or not. I’m sorry, but in any 3D film, the glasses cut out the bothersome ghosting. This reviewer must have grown up with poor TV reception in West Virginia.

Tech info on RealD from wikipedia

RealD 3D cinema technology uses circularly polarized light to produce stereoscopic image projection. Circular polarization technology has the advantage over linear polarization methods in that viewers are able to tilt their head and look about the theater naturally without a disturbing loss of 3D perception, whereas linear polarization projection requires viewers to keep their head orientation aligned within a narrow range of tilt for effective 3D perception; otherwise they may see double or darkened images.[2]

The high-resolution, digital cinema grade video projector alternately projects right-eye frames and left-eye frames 144 times per second.[2] The projector is either a Texas Instruments’ Digital Light Processing device or Sony’s reflective liquid crystal display. A push-pull electro-optical liquid crystal modulator called a ZScreen is placed immediately in front of the projector lens to alternately polarize each frame. It circularly polarizes the frames clockwise for the right eye and counterclockwise for the left eye. The audience wears spectacles with oppositely circularly polarized lenses to ensure each eye sees only its designated frame, even if the head is tilted. In RealD Cinema, each frame is projected three times to reduce flicker, a system called triple flash. The source video is usually produced at 24 frames per second per eye (total 48 frames/s), which may result in subtle ghosting and stuttering on horizontal camera movements. A silver screen is used to maintain the light polarization upon reflection and to reduce reflection loss to counter the inherent losses by the polarization filters. The result is a 3D picture that seems to extend behind and in front of the screen itself.[3]

Tech info on Dolby 3D from wikipedia

Dolby 3D uses a Dolby Digital Cinema projector that can show both 2D and 3D films. For 3D presentations, an alternate color wheel is placed in the projector. This color wheel contains one more set of red, green, and blue filters in addition to the red, green, and blue filters found on a typical color wheel. The additional set of three filters are able to produce the same color gamut as the original three filters but transmit light at different wavelengths. Glasses with complementary dichroic filters in the lenses are worn which filter out either one or the other set of three light wavelengths. In this way, one projector can display the left and right stereoscopic images simultaneously. This method of stereoscopic projection is called wavelength multiplex visualization. The dichroic filters in the Dolby 3D glasses are more expensive and fragile than the glasses technology used in circular polarization systems like RealD Cinema and are not considered disposable. However, an important benefit of Dolby 3D as compared to RealD is that no special silver screen is needed for it to work.

Discovering peripheral vision

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I went home from my first appointment and extensive eye exam on Tuesday with instructions to tape the center 1″ of my glasses and discover my peripheral vision system. I emailed my vision therapist the next day:

You told me to “have fun” with my occluded center vision and heightened peripheral vision. I have to tell you— I’m having a blast!

Seriously, I’ve noticed several amazing things (and it’s only half-way through the first day):

  • I automatically go up and down the stairs without reaching to feel the right wall
  • I saw myself go THROUGH a doorway! I was so thrilled I turned and went a back THROUGH the doorway about 3 more times (and then laughed at the cat staring at me and meowing from the middle of the kitchen floor.)
  • I am more aware of my the muscles working in my feet, ankles and legs, and am walking without looking at my feet, or looking a short distance on the path in front of them.
  • I feel taller … more erect … chin up more.

Fixing My Gaze finally arrived, and I am already half way through it. It turns out that the process of perceiving THROUGH has a name: optic flow. Barry writes

As I continued my vision therapy and became increasingly aware of my peripheral vision, I was able to tap into a phenomenon called optic flow. When you move forward, objects to the side of you appear to move backward. This optic flow is fastest for objects oriented at 90° to your movement, and the closer objects appear to you, the faster they appear to move … Cinematographers and video game designers have figured out how to create illusions of motion on flat screens by simulating optic flow. (p. 84)

Perhaps that’s why, every time I go through a doorway, I can almost hear the hum and “whoosh!” of a surround-sound theater space portal!

I’ve since realized I did learn to rely on peripheral vision in my mid-30s, when I was on a worship dance team (there was grace enough for a girl with two left feet to dance in church). I had to look out of the corners of my eyes because I needed to know where everyone was and what they were doing to stay in sync and to keep in my designated “window” in the choreography.

It just never occurred to me to use it always.

With my peripheral vision, I am able to use both eyes at the same time. Perhaps that’s why my body feels more balanced with the occlusion than without.

I am using these new glasses every chance I get!

center-occluded glasses

My new sno-occluded glasses (The Sno Seal is less visible than tape; and the beeswax won’t mess with the carbon lenses. I used the tape to get a straight line, and applied the wax with a very soft watercolor brush.)