Tim Samaras' "Big Kahuna" Camera

Discussion in 'Equipment' started by Ben Holcomb, Aug 11, 2015.

  1. Ben Holcomb

    Ben Holcomb Digital Janitor
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    As some of you may know, the "Big Kahuna" camera landed at the University of Oklahoma after Tim's passing in 2013. It was given to one of the biggest lightning researchers in the country - Dan Peterson. Dan has moved on from OU, accepting a job in the Washington D.C. area, so the camera was given as a project to myself and Shawn Riley, the other IT guy for the School of Meteorology.

    I've finally had a chance to get a run down of the camera and do a little playing with it today, and wanted to update the Stormtrack community about it, since many are unaware of the challenges.

    My first impressions are that it's a somewhat complex system. The only moving part is the mirror inside, which spins up to 1000 RPS with gas whether it be compressed helium, nitrogen or just a simplistic air compressor. There's challenges with each type of gas, cost being a big factor for nitrogen and helium. With that said, the mirror can only spin for 30 seconds to a minute at those high RPM's before becoming too hot since it is a mechanical mirror that uses bearings.

    The 10MP camera sensors are mounted around the outside, 82 of them in all. There is a frequency counter that fires each sensor in a series as the mirror spins in the camera. Each of these sensors are connected with USB 2.0, so it is somewhat slow to download images off, taking 20-25 minutes to download images.

    The Camera is more like a telescope with such a long focal length as well. The government originally used the camera to take photos of the atomic explosions, so they would have the camera a long distance away and focus the lens on a fixed position before running it (it was film). Focus seems to be a big problem, and may not actually be solved easily. There's an extra camera mounted to one of the spots instead of a sensor because we theorize Tim was trying to use it to get focus correct. It's a cheap photo sensor that was probably hooked up in some sort of fashion.

    The lenses for each spot are also f stop 26. This seems like it may be a problem as well for us, as even the brightest lightning strike may be hard to capture with such a high f stop, especially at very short exposures (microseconds)

    The weight makes moving the camera easily quite prohibitive, so getting a lightning strike here in Norman from the NWC seems like the best bet. Unfortunately there's very small windows to do so where strikes are close enough to capture with the camera.

    This project will definitely not move very fast, but I will update this thread if I have any success in getting the camera working. There's a lot of obstacles, but it would be nice to capture Tim's dream.
     
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  2. NealRasmussen

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    What will be the end frame rate?

    And also... Carry on, good Sir!
     
  3. Ben Holcomb

    Ben Holcomb Digital Janitor
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    Tim spoke to folks at 2013 ChaserCon about it. It depends is really the answer to the end frame rate. We'd like to do a million fps, but capturing lightning while only being able to spin the turbine for 15-20 seconds tops seems like a pipe dream.

     
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  4. Jeff Duda

    Jeff Duda Resident meteorological expert
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    I think Tim had told me it was capable of 1 million FPS. Not sure if that was his predicted maximum potential or if it was actually realized. I don't think he ever got a quality shot of a CG with it, but I think Danyal did. He presented some pretty cool stuff in an OU SoM colloquium about two years ago. Fascinating stuff.
     
  5. Ben Holcomb

    Ben Holcomb Digital Janitor
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    It hasn't ever gotten a shot of a CG as far as we know. I've been going through some of the old images, but as you can imagine they aren't easy to go through. I've found some decent pictures from 2013 of Paul, so Tim was apparently able to at least get the camera semi-focused and overcome the f stop issue somehow. I imagine he was running low FPS though to get it running, perhaps spinning the turbine/mirror by hand.
     
  6. Jarod Carlisle

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    Man, what an incredible undertaking! Hope you have success in realizing Tim's dream, that must be quite an honor.
    On a side note, after watching that video it's easy to see why he was so well liked and respected. I can only hope to some day meet a person of that intelligence and charisma.
     
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  7. James Hammett

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    You'd probably need an air bearing for continuous service at that speed. 15-20 seconds could be workable depending on the duty cycle. If it could handle a number of those runs over the course of a particularly active lightning storm the odds of getting a capture wouldn't be too bad. Assuming empty shots could be deleted off and everything reset quickly enough.

    Sounds like a huge engineering challenge regardless. Especially the f-stop...can't imagine anything of usable quality with that and the exposure time a very high frame rate would demand.
     
  8. Robert Forry

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    Man alive, I'm pretty sure I stood pretty close to the guy who shot this in Denver (as I reviewed my pics from the event). It's a truly amazing device, and with my mechanical background, I'd love to work on that thing too.. Good luck with it Ben!
     
  9. NealRasmussen

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    Any chance of a different lens? To get a wider view and better f-stop? F29 would show the main channel, perhaps well, but I'd doubt the step leaders unless those chips are way down on the EV range, like a Sony Nightvision++.
     
  10. Ben Holcomb

    Ben Holcomb Digital Janitor
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    A lens would be an option, and wider angle would be nice since right now it's essentially a telescope. The problem is, finding someone to make me a lens that big is not going to be cheap.
     

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