Frozen Pi — An Affordable Bullet Time Recorder


What happens when you strap 48 Raspberry Pi cameras together with nearly half a kilometer of network cables? You get your own bullet time capture rig.

Originally inspired by the unique film effect of the  Matrix and an old BBC documentary called Supernatural: The Unseen Powers of Animals, the owner of PiFace decided to try re-creating the bullet time effect himself.

To create the rig they’ve taken 48 Raspberry Pis, each with a PiFace controller board and the standard camera. The controller board allows the Raspberry Pi to be used without a keyboard or mouse, so all the network cables have to do is send a simple code to each pi in order to take the pictures. A simple laser cut wood profile is used to snap them all together into a giant ring.

While 48 Raspberry Pis is a lot, they think this is a reasonable project for a classroom environment — besides, how cool would it be to go to school and film your own bullet time stunts?

Of course we have seen lots of bullet time rigs before, but it looks like this one will give a bit better of an effect. If you don’t have the cash for that many cameras — how about a single GoPro and a ceiling fan? Hackaday Alum [Caleb] even managed to do one with a lazy susan!

[Via Adafruit]


  1. When I read “bullet time”, I thought of this:
    Then I said, “Oh. The Matrix. Wasn’t that a long time ago?”

  2. fartface says:

    Far more affordable to just rent that many gorpo’s.

    • m1ndtr1p says:

      Why rent when you can own? Besides, there are far more things you can do with a bunch of Raspberry Pis than a bunch of GoPros…So buying a bunch of Raspberry Pis would be a great idea, especially in that type of setting (school/classroom)…

  3. supershwa says:


    Furthermore it spawned an awesome idea…share later. ;p

  4. scuffles says:

    I can understand needing multiple Pis and multiple Pi cameras. As you physically can’t do it without them but having an interface for each and every camera seems needless. I mean they are all networked… At most one of them would need the PiFace and you code that as command and control for the rest.

    Still an interesting project tho :)

    • DarwinSurvivor says:

      I’m pretty sure I saw IR receivers on all of those. If so, you could just select an offset for each one (which the little scroll-wheel they added does) and trigger it with an LED or mirror on the ceiling?

  5. Stanto says:
    • Truth says:

      That to me looks like the cameras are not all pointing at the middle, and are not all level – some are pointing slightly up and some down. It is a calibration issue that could be sorted out iteratively by calibrating each camera module. Or even fixed in post by reducing the image size to clip the images to make them all fit as they should.

  6. jpnorair says:

    That’s a lot of cabling. I bet the same could be done with a bunch of cheap, linux smartphones over wifi. Best of all, you could just resell the phones if it didn’t work. :)

  7. rexxar says:

    I wonder if this would be any good as a 3D scanner? Put a large object in the middle, and slowly raise the ring as it takes pictures.

  8. AnthonyD says:

    Glancing at the picture I thought it was mini particle accelerator

  9. vonskippy says:

    Why 48? Was there any calculations done or did it just seem like a good number?

    • AKA the A says:

      Non-remainder division? (English is not my primary language…) Gets you exactly 2 seconds of 24p video for really slow bullet time ;-)

    • Truth says:

      I didn’t give that a second thought, I just assumed that they where using a 48 port network switch.

      I’m just now wondering why I have heard them always called 48 port switches when in fact most 48 port switches normally have 2 additional fibre ports for primary and secondary redundant links to the network backbone, so technically they should be called 50 port switches.

  10. DainBramage1991 says:

    Not my idea of affordable (Looks like about $3300 from my sources, though I’m sure the parts can be had cheaper with some hunting), but still less costly than 48 GoPros.

    Nice hack, though.

  11. StinkySteve says:

    Can you not attach multiple cameras per pi? Even if you have to go the usb webcam route?

    I like the bullet time effect, I saw a gopro video similar to this the other day. The only problem is the amount of time it takes it editing. In the sample Youtube video you’ll notice they’ve just mashed together the images one after another, with no movement of the actor.

  12. but has it been done in porn yet hmmmmm

  13. Sven says:

    You spend all that money on cutting the fixture, and you make it too small to do any actual stunt inside… Even if you sit down you can’t get a whole person in shot…

  14. ERROR_user_unknown says:

    Could this be used for 3D motion capture ??

  15. eanao says:

    Pi’s are great and this is definitely an interesting project, to all the go pro’ers I say no one would really buy a gopro when you could have an sj4000 right? Well not on my budget anyway

  16. DougL says:

    So very cool, thanks for sharing this.

  17. John U says:

    Is it just me that thinks a ring of model railway track / scalextrix with a couple of GoPros running round in circles on trains/cars would be worth a shot?

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