Friday, May 29, 2015

Time-Lapse Sakurajima


Direct youtube link


After making the time lapse movie of Sakurajima back on the 13th, I decided that I'd try visiting various viewpoints around the city and turn it into a "day in the life of" video that would span sunrise to dusk. On the 20th, I got up at 6 AM, when the sun had already been up for well over an hour, and ran down to Dolphin Port to start recording. The battery ran out after 4 hours, and by that time, even though I had put on sunscreen and retreated to the shade of a gazebo, I was pretty badly sunburned. The next day, I went over to the Xavier landing spot and recorded from about 10:30 AM to almost 3 PM, when the battery ran out again. It would have been nice to have a second battery, but moving the camera would have messed up the shots, and it'd have kept me out in the sun longer. On the other hand, there was a big eruption at 6 PM that got mentioned on national news and I would have been in the perfect location to capture it. Finally, after work the following day, I returned to Dolphin Port, closer to the ferry docks, and taped from about 5 PM to a little after 7 PM, when the sun was down far enough that the camera was having trouble focusing in the low light.

The Canon PowerShot stores individual interval photos in separate folders, 200 files together. At 1 shot every 30 seconds, and a little over 4 hours per battery charge, that's 510+ photos in 3 folders in one outing. I used Window's MovieMaker to stitch the photos together into one movie per 510+ file batch (any more than that in one project and MovieMaker starts "losing" files during playback, destroying the project file). I rendered movies at 0.1, 0.15 and 0.2 seconds per frame to compare the results. 0.1 sec gave me very smooth movements of the clouds and ferry boats, but everything was too fast to follow easily. 0.15 was "chunkier", but the playback speed was easier to watch. 0.2 was too slow. After rendering all four videos at 0.15 secs each, giving me four files of about 1.2 minutes apiece, I started a new MM project file and copied the four smaller video files into it to get the final movie. While I was at it, I wrote a VBScript to rename the May 20 photos to reverse the filename order. This gave me one more small movie with Sakurajima running backwards, which I appended at the end of the main movie and ran at 0.03 sec/frame.

This left me with the question of what to do for a soundtrack. I was thinking about trying to match up Kraftwerk or Tangerine Dream songs with various parts of the video, but that would leave me with copyright problems and the possibility of having to pull the video from youtube if they muted my video again. At about this time, I was writing up the Vocaloid P review for volume 18, and the Singer-Song Writer tutorial was walking me through the process of using pre-written phrases for different genres to make a full song. I was experimenting with the Trance phrases and some of them matched the timelapse actions pretty closely. Trance also has sound effects like explosions that I liked for emphasizing the volcano eruptions. So, when I finished the Vocaloid write-up I sat down with SSW for a full day and tried to copy-paste a song that lined up with the timing sheet I wrote up. I quickly ran into a problem where the playback speed of the sheet music wasn't in integer units of seconds. This meant that I couldn't just write a song based on 2 beat or 4 beat measures, because some of the actions occurred 2.4 seconds apart, and others at random intervals. I looped the drum track to last the length of each mini-movie and then tried to get the other instruments and sound effects as close to the action in the main movie as I could. Some of the explosions are half a beat off (either too early or too late) but I think the over all soundtrack works ok.

For the final mini-movie, I extracted 24 seconds of the music from the middle of the song, reversed it in Audacity, sped it up to drop the playback time to 12 seconds, and put that into MovieMaker. It's not perfect, but it's good enough.

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On May 21st, I went down to the Francis Xavier landing site (where Xavier, the first Jesuit priest to visit Japan, originally docked in Kagoshima in 1549) to shoot part of my time-lapse series of Sakurajima. I'd grabbed two Coke-One Piece "leisure sheets" from the grocery store to have something to sit on in the shade. They were very convenient.



Having two cameras works out well when you want to use one to show the set-up for the other.



The landing point is also the site of a community center. There was one hawk that kept flying really low around the building, stopping on the roof a couple times.



He knew the good camera was being used to take photos of the volcano.



I hate it when birds mess with me like this. They never pose when I have the good camera out.

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