This Video Is 2D And 3D Simultaneously: the Pulfrich Effect

This Video Is 2D And 3D Simultaneously: the Pulfrich Effect

Hold on tight, because with a stabilised camera shot and a pair of sunglasses, you’re about to see a video that works in both 2D and 3D at the same time. The technique’s called the Pulfrich Effect, and this is how it works.

The BBC’s terrible 90s Doctor Who special, Dimensions in Time, can be seen here, complete with its Noel Edmonds-filled framing:

Camera and sound: Matt Gray /

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73 Responses

  1. Tom Scott says:

    This was originally just going to be a test shoot, but then Matt and I played the first take back and both shouted “whoa” when it worked right away on just a phone screen in daylight. If it worked or didn’t work for you, let me know the details – what are you watching on? What’s the lighting like near you?

    • Ath Athanasius says:

      It certainly appeared to work for me. I wear prescription glasses for short-sightedness, but fortunately also have prescription sun glasses and managed to hold the correct lens from each pair to the correct eye to show the effect. It’s subtle, but definitely looked different to watching just through the non-sunglasses.

      You definitely “popped out” when you started moving with the rotating camera again at 02:35 or so.

    • Fireork says:

      Tom Scott Sitting with my phone in bed, the room is kinda dim, due to the light being off, but the sun is going through my window

    • rokenwolf says:

      “Accidentally” kept my 3D glasses from a 3D Imax screening of Star Wars and viewed it on a 17″ laptop. Can confirm it works very well! A brighter environment helps to work more quickly but doesn’t seem to be strictly necessary.

    • Kim Forsberg says:

      Decently well lit room, medium shades , and f.lux at 4500K in case that would matter. Works great!

    • samuel young says:

      i didnt use a pair of sunglasses and it worked for me. i used a bright lamp with half the screen and the other side is dark and its 3d

  2. ChildishGiant says:

    Looks super low res

  3. MrAdeelAH says:


  4. REMLostmyreligion says:

    Before clicking: THIS IS CLICKBAIT
    When watching: Nevermind…

    • FabrΓ­cio Lara says:

      Having just watched the park bench reviewing the GoPro Fusion, I thought the video would be about it. I was happily surprised!

  5. The Suicidal Muffin says:

    Everyone knows 2D > 3D

  6. therese294776 says:

    Lying in bed squinting? HOW DID YOU KNOW.

  7. Politic Revolutionnaire says:

    I always love it when you keep the part where you celebrate doing it in one take, please continue to do this.

  8. Brian Campbell says:


  9. Vivienne Gucwa says:

    Trippiest video ever? But seriously, this was so bizarre to view since I view everything with only one eye. For me, you appeared slightly 3D fuzzy at times and then normal and that effect would come and go and the whole thing kind of reminds me of the weirdness of an Aphex Twin video or something like that (I should note that 3D usually never works for me in general). Was there camera movement at 2:18 or is it just the brain attempting to catch up with the motion? That’s the point where the camera person appears to have stopped moving but I swear the video still seems to move (this is the most non-sensical comment I may have ever posted…ever πŸ™‚ )

    • Southern Illinois Drivers says:

      The camera was still moving a bit but you were probably seeing some Motion Aftereffect. It happens in cars when you’ve been driving a long while and come to a stop, the road appears to rush away from you.

    • the 117 doctor says:

      Vivienne Gucwa actual camera movement

    • Goldyray Yeazle says:

      I’m confused… You view everything with one eye and 3D doesn’t normally work for you, yet you were able to experience it slightly here. Are you closing an eye or is it something you can’t help? Old SNES games with the differently scrolling backgrounds were great with this type of 3D back in the day if you want to check it out with an emulator. I’m thinking most 3d games with a free camera may produce the effect as well. When I had the glasses for this efffect when I was a kid I watched everything with them. Anyway, you just weren’t clear about why you watch most videos with one eye. I catch myself doing that when I get sleepy, I’ll often close one eye without realizing it and continue doing what I was doing until it’s pointed out to me.

    • Heath Mitchell says:

      Vivienne Gucwa It moves a bit at 2:18

    • rashkavar says:

      In all honesty, I think the cameraman is slightly dizzy after having to spin for two minutes, so he’s having slightly more trouble than usual holding the camera precisely steady.

  10. Martin El-Kher says:

    I feel dizzy af now…

  11. Ilya Kiselev says:

    Squinting one eye actually did the trick for me!
    People without sunglasses, do try it out.

    • chronousnemesis says:

      Yup, it actually works. And my right eye hurts.
      The bokeh effect (high pixel on Tom, and low pixel in tree background) actually help to distinguish two layers apart.
      So you can see the 3D effect.

    • StarmanF says:

      Lel wish there was exactly one comment talking about the squinting effect that everyone would upvote, people who didn’t think to try squinting might miss out if this doesn’t get to the top

  12. Jii Koo says:

    *Goes to get sunglasses and waches again to see if there is a difference*

  13. SteamEmpire says:

    if people still have trouble getting it to work here’s a few things
    -Put the quality to the highest there is in this case 1080p 50fps
    -make sure where ever you are watching this its nice and bright
    -Have the sunglasses cover your right eye since the video is moving from right to left. dont cover both eyes

    bonus point
    I’m gonna need a bucket to to watch this again

  14. Chan Wee Kiat says:

    i feel almost like vommiting due to the moving

  15. my opinions are facts says:

    Great, now I gotta track down some sun glasses

    • Sjuns says:

      Actually it worked fine for me without any sunglasses, I just squinted with one eye.

    • Buddy Clem says:

      Sjuns It worked for me too! Specifically, in bed, on my phone, squinting my right eye, and not holding my at arm’s length, and not turning the screen brightness up. How about that?

  16. Houston Hilburn says:

    And they said my sunglass monocle was useless!

  17. DerParadonym says:

    I can see the red shirt under the sweater. Thank god that’s tom again…

  18. Paul Paulson says:

    It works for me by forming a small hole with the index finger of my right hand very close in front of my right eye. The lighting conditions are not the best here, but it still works. I put the screen (tablet) around a meter away so i can still see most of it through the hole. And it darkens the image for the right eye enough to get the 3d effect without any glasses.
    Fun fact: If you have to wear glasses, the same method with the finger can be used to see a sharper image without the glasses.

  19. Ami Yamato says:

    There was a music video by Seal which also used this effect. The VHS came with glasses which had the right eye darkened.
    I can’t remember which song though, sorry.
    There was also an episode of “Third Rock form the Sun” which did this too.

  20. AntVenom says:

    Had a pair of polarized sunglasses next to me, tried this…mind BLOWNNNNNNNNNNNN. WOW.

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