November 1, 2017

'MegaBots': What Happens When You Stick Cameras Inside Killer Robots?

'Mythbusters' DP Scott Sorensen rigged cameras inside giant battle robots for the upcoming 'MegaBots' series.

430HP. 16 feet tall. 12-tons. $2.5million. These sound like numbers for a boat, or maybe a tank, but they actually describe the American entrant in a Sports Combat Robot contest between MegaBots, Inc. from the Bay Area and Suidobashi Heavy Industry from Japan.

We bet you didn't even know that Sports Combat Robots were a thing. But they are, as detailed in the new web series MegaBots, which documents the build and battle process. We had a chat with cinematographer Scott Sorensen about the lengths he had to go to in working with our future robot overlords.

No Film School: Obviously any shoot with live fighting robots will present some challenges. How did you approach it?

Scott Sorensen: Initially, we started filming this thing like a year and a half before the actual duel happened because it took a long time to build the darn thing. From early on, I knew that we would need high-quality images from a small camera so something like the Blackmagic Micro Cinema would be a good fit for when we finally got into the robot, because of the expansion ports and the small size.

So we ended up using six Micros, and we ended up using them for lock-offs and wides, and a bunch of stuff before the robot was even built. But it was really cool, because on some of the bigger shoots, I'd have a camera on the Kessler Second Shooter, one on the Ronin-M, and one on a 14-foot jib. And they would just kind of live in their places throughout the shoot, and yeah, it was pretty neat.

"I'd have a camera on the Kessler Second Shooter, one on the Ronin-M, and one on a 14-foot jib."

NFS: So rather than having one or two "good" camera bodies, and rebuilding different setups each time, on this show you were able to take enough bodies out that it lives ready for you whenever you needed to use it.

Sorensen: Yeah, I mean, it's kinda nice having that many different cameras, or that many of the same camera, because if you're shooting something really simple, you can have a camera that's just built on a gimbal all day, and you're like "Oh, I want to get this quick gimbal shot", and then get it, and then set the gimbal down, and you've got options.

Credit: Megabots

NFS: I noticed that you guys really took advantage of the accessory port on the Micro Cinema cameras. Is that something you had any experience with at all before you worked on MegaBots?

Sorensen: No, no, none at all. I knew it was there, I knew it could do some cool things. And I will say it was actually scary intuitive once I got into it.

I did get some advice from one of my dad's friends, who does a lot of RC flying. He was able to recommend the transmitter and receiver set up, but then once I had all the parts, it kinda just came together. It was pretty intuitive, and I think that the parts I ended up buying for it could have done a lot more than I was asking of them. Like, just the record function on all of them, cause they all had fixed lenses, they all have the Rokinon 7.5mm lens, because the spaces are so tight in the robot, so we didn't use lens control since it was fixed. There's a bunch of features that you can utilize with the RC system that I just kind of brushed over and ignored cause all I needed was record.

Credit: Megabots

NFS: Even that, having an easy record, stop record, where you don't have to do that thing where you just leave it running for seven hours—

Sorensen: Oh yeah. Yeah, for one thing, this is a system that I would have killed for back in MythBusters days, cause we had so many freaking cameras all over the place. You'd end up just sprinting from camera to camera in a hundred degree heat, and then, you know, before you'd get to safety, and then you'd have to wait for the bomb squad to go in and cap into the explosion and then they come back and then, oh maybe there's a misfire, and then they go back over, and you're just kind of watching the clock thinking, "Oh crap, I'm gonna run out of battery or media or something here." So that was amazing, just be able to sit in video village, and see that everything was good, everything was rolling, and we didn't have a crap ton of media to go through at the end of the day.

"This is a system that I would have killed for back in MythBusters days."

NFS: And what were you using to get wireless video out of the cameras inside the robot?

Sorensen:  I was using a Teradek system for the wireless. But the trick was to go from all the cameras. The MegaBot had four cameras in it. All four cameras then had micro convertors to go from HDMI to SDI. And then I ran the four SDI lines to a MultiView 4 and then ran that into the Teradek.  So I could have one wireless feed from each robot that had all the shots.

Wiring to the accessory port.Credit: Megabots

NFS: The other benefit of having remote start/stop is you were probably turning over a lot less wasted footage to post, so you were able to roll and cut for just the moments that worked.

Sorensen: Yeah. On one of the last videos we did with the MegaBots, it was like the Mark III debut video was the last big video before the duel. I didn't have the system built yet, like the shoot kinda came together really quick because the robot had to get put onto a boat and sent to Japan, so this was kinda this last minute thing where the features, all the movements on the robot, had just been programmed or were being programmed as we showed up. 

Oh, it was like everything that this robot's done is the first time anyone's ever done this. So a lot of the shoots, we'd get there, and then there's still work to be done. But that first shoot in particular kind of happened quick so I didn't have time to build the system yet. And we ended up filming that video over two days I think, and it was kind of a nightmare because the robot, when it was turned on, had an exclusion zone. You know, you couldn't go near the robot cause it's very new and you just wanna be super safe, so if something happens, like the robot shuts off and the arm falls or droops or something, you want everybody far away.

So what we'd have to do is have the robot turned off, climb the robot, turn everything on, and plugging a small monitor into each camera to make sure it was all good to go. Then climb down the robot and get into position. But then it would be like ten minutes before the robot was powered on, warmed up, like stood up and ready to go. So you burned through ten minutes, ten fifteen minutes of record time right there before anything happened.

Credit: Megabots

So remote record ended up being key for the duel because it's just quick. And all the cameras were powered from inverters inside of the robots, so I was never worried about losing battery life, never worried about media.  

One of the coolest things about that shoot was just kind of how freakishly well that system worked. I guess I would've expected it to be more complicated but, even just like programming the transmitter to have four channels going to one receiver and two channels going to another receiver. It was all really basic and, you know, crimping servo cable connections so you had the right length of wire in the robot, like it was all really straight forward. I was really pleased.

"Once I had everything in the room, I had cameras plugged into the receiver and recording within like a morning."

NFS: How much time do you think it took to put it all together to make it work?

Sorensen: It took, probably took about a day, well no, I mean it took longer to gather all the materials than anything. I think once I had everything in the room, I had cameras plugged into the receiver and recording within like a morning. It was a matter of gathering everything and then crimping servo cables took longer than programming did. I think I watched the last half of the last season of Justified while just standing there crimping cables.

NFS: Is power supply something you interfaced with the robot designers? You know, you were like, "Hey guys, at least part of this is we have to shoot this, so can you give me some accessory power?" And were they totally good with that?

Sorensen: They were totally good with that. It kind of happened the few days we were setting up in Japan. We filmed it in Hayward, and then like the next couple days it got broken down and put on a boat and sent to Japan.

Once we were on set building everything up, we worked with them to figure out what Japanese inverter would work in their robot, cause they had a 12 volt system and a 24 volt system in the MegaBot, the newer one. We ended up just building a, putting an off-the-shelf inverter in the very back of it and ran the whole system off of that.

NFS: I would assume the robot designers wouldn't want to give you any power because power useage is tightly controlled and there isn't excess to spare, but I guess there's already so much power coursing through that thing?

Sorensen: Yeah, there's a fair bit of power just for all of its electronic systems. I think the 24 volt system didn't have a lot of power being used on it, so it was fairly open. They're very accommodating, and I think the goal for the Mark III was that all of the systems were integrated. It wasn't just, oh there's a car battery in the back with an inverter taped to it. Everything is kind of connected, which is pretty cool.

"It's just kind of good practice not to walk under the arm that weighs a couple thousand pounds."

NFS: Did the robots feel more or less dangerous than normal MythBusters experiment where they blow a lot of stuff up?

Sorensen: The robots are kind of a different animal. With the robots, it kind of feels like working around heavy equipment, or it feels more similar to that. There is an element of, well this thing is a prototype and maybe this is the first time that this hydraulic system has been pressurized, so there's a potential for failure.

You just wanna make sure that the operator knows where you are, and you're always aware of where the big giant robot is. And there's kind of basic safety things, like don't walk under the arms. There's like safety lock-outs and stuff in place, but it's just kind of good practice not to walk under the arm that weighs a couple thousand pounds.     

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