Bullet time lightning

A while back, I took some photos of my spark gap Tesla coil running.

Although I did get some nice shots, I couldn’t help but feel that they don’t quite capture the full experience of a real live lightning machine. While I can’t do much to recreate the visceral smell of ozone and nitrogen compounds formed by the ionizing sparks, or the reverberating whine of the beautiful but deadly spark gap, I did have an idea for bringing another aspect of the lightning show to the interwebs.

3-D lightning! (Be sure to watch it in HD if you have the bandwidth.)

I made a ten-camera array of Canon A470s, and configured them to work as a single 70-megapixel 10-angle camera.


Why that particular camera? Partly because I found someone dumping a bunch of them on eBay for cheap, but also because they run CHDK, the infamous scriptable firmware for Canon cameras. This let me write some code to streamline the process of taking ten photos all at once, and then get them off of the cameras in a reasonable manner. By wiring all of them to the same 10-port USB hub, and using CHDK’s syncable USB remote feature, I was able to wire up a single button to make all of the cameras fire at once. Collect all the photos, find all of the good ones that are actually in focus, get them aligned and color balanced and scaled, and away you go. Bullet time lightning.

bullet time lightning

This was one of the more challenging projects I’ve taken on in a while. I had to build a physical mount to hold all of the cameras, wire them together to a repurposed PC power supply, recompile CHDK to eliminate as many unnecessary camera keystrokes as possible, write some scripts to facilitate taking and retrieving the photos, then shoot the actual photos without accidentally frying the whole rig. And, of course, build and operate the Tesla coil itself, edit together the stills, and compile the whole thing into a possibly entertaining vid.

I want to take a lot more footage with this camera, but I also wanted to release the results as soon as I could. So here you are.

Aside from Tesla shots, what would you shoot if you had a bullet-time style camera?


25 thoughts on “Bullet time lightning”

  1. LOVE IT! if you use Optical flow to interpolate the frames you’ll get a much higher quality presentation. Shake, Nuke or a current version of After Effects should be able to do this for you.

  2. What about making each camera fire a few milliseconds later than the previous one? Would add the dynamics of the movements of the discharges, which could add some more awesomeness.

  3. Thanks for watching, everybody!

    Re: time shifting each shot, this is already in the works. I’m currently fighting some strange interactions between CHDK and these cheap cameras, which makes it difficult to get repeatable results.

    The tool chain from “click” to finished movie is also rather long and painful. Expect updates as the process improves!

  4. You can work around the cameras if you just shift the timing of the signal to the individual cams. You then could control them individually, and generate the shifted-timing signal by e.g. a microcontroller. Just a thought… 🙂

  5. First, let me say WOW!! I love Nicola Tesla and his infamous coils (and other technologies) he brought us. If he were alive today I am sure he would find this intriquing. Great idea!

    There are so many things to shoot where do you start. I think freezing snowflakes against a dark background would be cool. Smoke! Yeah that would be cool to capture in 3D.

  6. you download all pics at the same time from 10 cameras?
    your scripts run in SDM?

  7. Fantastic, Rob! You hit the jackpot getting 10 of the same model of PowerShot. I’m getting them off kijiji in singles and it’s painful.


  8. 1st, the video and the experimenbt is great. Good work

    2nd, the link to the CHDK script at “This let me write some code to streamline the process of taking ten photos all at once…” has disappeared. Is it possible to have a look to it?

    Thanks in advance.

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