Last weekend, Trevor and Maira and I took the balloon mapping kit I received as a reward for backing the Public Laboratory Kickstarter project out for a spin. The kit is simple and inexpensive by design. It contains a 5.5 foot balloon, a very long string and winder, rubber bands, and assorted clips, rings and carabiners. You provide a camera, a soda bottle camera rig, and helium.
Public Laboratory has made the kits for “grassroots mapping”, but for this trip up I was just interested in getting some photographs from the air and seeing how that goes.
We chose to fly at Alta Plaza Park in Pacific Heights, because it was close to where the helium tank rental was, and the tank was about 40 lbs. Set-up was easy: Public Laboratory provides really good directions in the kit, and up-to-date video supplements online. The soda-bottle camera rig was a bit more complex than I had thought going into it, but Maira was a champ about putting it together.
Of the 600 photos or so we took, we got a handful of interesting ones. That may seem like a low yield, but I think it’s not bad for a first round. Here are some of my favorites:
To get a sense for the whole collection, I put together a video that speeds up the photos, taken about a second apart, to 6fps. ((I used the program mencoder to make this video. The command I used is listed in the video description on YouTube, should it be helpful.)) The audio is from the public domain recording of the Hungarian Rag played by Pietro Deiro, found on the Public Domain Review.
I underestimated the complexity of grappling with the camera and the balloon in the moments before flying. For one thing it was just a bit too windy to be flying a balloon, but for another, we ran into an annoying technical bug. The camera I use, a Canon Powershot SD 870, has the necessary “continuous” mode, but defaults to single-shot mode each time it gets powered on.
That meant futzing with the controls once the camera was already on and in the harness, and trying to avoid any buttons. I think the photos we got are washed out because I knocked one of the settings off of automatic, but I couldn’t hunt down which.
Fortunately, each of these problems are solvable. Picking a calmer day, a clearer ground, and a heavier payload should help with the first. ((On a windy day, I could also take a kite out instead of a balloon, something I’m definitely looking into.)) For the second, I’ve installed a firmware extension on my camera called CHDK, or the Canon Hacker’s Development Kit, which allows for finer-grained control of camera settings. Before the next flight, I’ll be looking into the best configuration.