More 3D magic

30

A couple of things.  First, the dates for the US tour for 59 Seconds have now been confirmed…
Jan 5 & 6–New York
Jan 7–DC
Jan 8–Boston
Jan 9 & 10–Vegas
Jan 11–Seattle
Jan 12– San Francisco
Jan 13–Los Angeles

More details as I get them.  Second, there is something of a 3D revival going on at the moment (including several horror films and a great magic special on C4 last night), so I thought it would be good to introduce The Pulfrich Effect.  For most 3D effects you need to make a special film and have people watch it with odd glasses.  However, it is possible to get the same effect on ‘normal’ footage.  All you need to do is have someone cover one eye with something that darkens the image (e.g., sunglasses or one lens of 3D glasses) and view a scene with lateral movement.  Interestingly, the effect does not work for everyone, but give it a go with the following clip (kindly sent to me by Chris Lawrence)…..

According to Chris, the effect works well with football games – meaning you can turn a 2D game into 3D.

Did it work for you?  Any idea why?

30 comments on “More 3D magic

  1. Fran6co says:

    Wow ! Unbelievable !!!
    It worked perfect for me @_@

  2. Lafayette says:

    I remember when there was all that hoohah about the Lovers’ Guide, and sexually explicit educational videos. A company created a 3d Karma Sutra tape, then found they couldn’t get it certified by the BBFC, because 3d always means fun; it didn’t qualify as education. The company re-edited it, but then put out an uncut version that wasn’t marketed as 3d. It used exactly the same footage, though, and because it had been shot so that it could create 3d with the Pulfrich effect, you could still watch it in 3d regardless.

  3. Chris says:

    Some years ago a special Children in Need edition of Eastenders used this effect.

  4. Fergus Gallagher says:

    Yes, and there was a similar Dr Who one. The camera was constantly whirling around the actors. I think “Tomorrow’s World” either did it or explained it.

    I believe it was something do with the mind’s processing of dark images taking slightly longer than bright images, so the moving camera gives the effect of two different “eye” positions.

    • A “dark delay” is my guess, too. It seems like a delay as the cause could be independently tested for by showing each eye the same video with one or the other getting a slight lag, and then compare that to the results of this Pulfrich Effect. Personally I didn’t really see any surprising effect, but the only filter I have handy isn’t that dark. It may also be that my brain is doing a fair amount of motion pre-processing already, because the regular video already looks kinda 3D to me.

    • fluffy says:

      The “dark delay” is how I’d always heard it explained as well.

  5. Henry Burrows says:

    Yes, it worked perfectly – with my left eye looking through a darkened lens the scene was suddenly in 3d. Trying it on my right eye resulted in a flat image. Nice effect!

    • Engywuck says:

      After downloading this test clip I tried different things.
      You may change the shaded eye after flipping the picture horizontally or playing the movie backwards. For more Information look up “Pulfrich Effect”.

  6. Zap says:

    Actually you can turn almost anything “3D” by simply closing one eye;

    the brain has *many* cues for deconstructing “depth” in a scene. Our binocular vision is only one, but the *strongest* one. So if you remove that (by simply removing one eyes vision), many other of them kick in.

    Try it on a movie some day, just close one eye, the apparent depth will increase… because it’s your binocular vision that is the main cue that the screen is really *flat*. Remove that, and you’ll have some interesting experience (as a fraction of the budget Jim Cameron is using for Avatar :) )

    /Z

    • Ded says:

      Yeah Zap, I know what you mean :D If I happen to be reading or watching something on the monitor with one eye closed (being lazy and leaning on my hand usually) eventually it seems like the image is miles away in the distance.. is odd.

  7. Daniel Pope says:

    If you look closely you’ll see the shadows on the central hub are also 3D! They float out of the screen a little way.

    I remember when the BBC did a special week using this effect. Eventually I got pretty bored of every shot panning or orbiting furiously to the right. But strangely, I didn’t notice the absence of 3D in the occasional static shots they cut in.

    My parents, who didn’t have glasses, said the movement made it look “more 3D” for them too; obviously parallax is a visual cue as well.

  8. Derek says:

    Amazing! I used a pair of C4 3D glasses and noticed how much more pronounced the effect was when I used the Orange lens rather than the blue one!

  9. Beth says:

    I can’t see it ;(

    Had a lesson in 3D the other day (red & green lenses) and I couldn’t see that either, something to do with the fact I have a squint. Unfair haha

  10. The Doctor Who and the Eastenders specials were one and the same. Carry on.

  11. Patrick Lehnen says:

    Did work for me. Cool ;)

  12. Adam says:

    Wow, that’s pretty impressive! I tried again with my right eye darkened and it didn’t work at all for me. Interesting how it’s so sensitive to this.

  13. Luisa says:

    it worked perfectly! but now my left eye feels strange

  14. namowal says:

    Wow, that’s weird.
    Now I’m curious:
    Does it work better depending on what’s being filmed (fast vs. slow things? Big vs. small?)
    Does it work for photographs? (I tried it on a still image of the clip and it seemed to slightly work, but it may have been my mind playing tricks on me)
    Do changes in eye filter (color, how light or dark, blur) alter the effect?

  15. FirstTimeCaller says:

    I didn’t have a pair of sunglasses handy (I’m in the Pacific Northwest afterall) but it seemed to work somewhat using reading glasses — didn’t seem to matter which eye. Definitely more of a 3D appearance than without the glasses.

  16. Chris Lawrence says:

    If you don’t have a filter handy try this instead. Place your fingertips right in front of your left eye as if you are trying to pinch your eyelashes side-on. Then start with your fingertips apart and slowly close them while viewing the video. At some point they will start to diminish the light coming into your eye and you see the effect.

    You darken the left eye if the lateral foreground movement appears right to left, and vice-versa if it’s left to right. The effect is caused by the darker image taking a fraction longer to reach your senses, which you interpret the same as if it was caused by depth, so you perceive depth. Swapping the filter should cause a pseudoscopic image but it’s much harder to override the sense of foreground and background in order to see it. This suggests to me that the brain is doing some contextual filling in from items in the scene.

    If you switch to a television channel that showing static (“snow”) then the effect causes the appearance of two planes at different depths – one containing dots going right to left, the other going the other way.

    You get a greater effect with a darker filter but not so dark that you can’t combine the two images. If the filter is coloured then it might make recombination more difficult depending on the colours in the moving scene, which might be why one works better than the other as well as one being darker than the other.

    Here’s a clip from The Matrix where you can see the effect, starting with a strong effect on the bullet whizzing towards you Lafayette’s comment on how it was used in an adult film made me laugh!

    Chris

  17. Flavio says:

    I’m not getting the effect, or maybe just a very slight depth.

    I did notice the spelling errors in the video, though :D

  18. Jane says:

    I can’t really see it

  19. SemiColon says:

    Didn’t work for me, either. Tried out some other ones on youtube and can’t get it with any of those. Guess I’m one of the unlucky ones.

  20. SteveG says:

    Yes, it worked. Generally my left eye is the dominant one and so with it darkened the effect was immediate. I had to concentrate to get the effect when i used the dark lens on my right eye.
    That was very interesting…

  21. Sally says:

    The image seemed very 3-D without doing any manipulations …
    Then tried sunglasses in front of my left eye, then my right; then tried closing my left eye, then right one – these changes didn’t seem to make a difference. ?

  22. Wilf says:

    I’m pretty sure I experienced it. Now to repeat the experiement…

  23. elbuho says:

    I used it with my third eye, worked perfectly!

  24. Hey,

    No plans for a Atlanta, GA appearance?

    We’d love you down here!

  25. eu armory says:

    eu armory…

    [...]More 3D magic « Richard Wiseman[...]…

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