Wesley's Tool-Box

While I have observed the International Space Station (ISS) making a pass in front of the Sun before, it was at a resort far away from home. Yesterday, I had the good fortune of witnessing a pass right at home. My daughter Celine wanted to help out, so I let her set up the equipment and we went to the parking lot to start photographing. We took the photos of the Sun together, and in three of the frames, the ISS was found crossing in front of the Sun. Here is the composite of the three frames set against the stacked 32 frames I shot in 14 seconds while attempting to capture the transit, both in the annotated and full version.

The last frame was really lucky, as it was taken just before ISS got out of the Sun's disk - 0.1 seconds late and we would have ended up taking two frames instead. SX50 HS's regular burst mode takes a photo every 0.43 seconds, so given the transit time of less than a second, this was the best outcome I could expect.

I do wish the fast burst mode, which can take a photo every 0.077 seconds, could take more than 10 photos at once, though. The transit prediction from CalSky is pretty accurate, but local clock error and human reaction delay can creep in. So I would need it to last at least five seconds or so. I should either wait for Canon to make a superzoom camera that can shoot longer bursts, or install an iPhone 5S, which can do 0.1-second burst shots for several minutes, on a telescope. I'm saying this because I missed the Moon - ISS transit on Saturday while using the fast burst mode.


Anyways, here's the animated version of the transit that illustrates the movement quite well. Come to think of it, this sort of pass would be hard to see in person with binoculars - ISS is tiny and moves quite fast, so unless the Sun is magnified really big, it'd be hard to notice.

Device: Canon SX50 HS
Settings: 1200mm - ISO 500 - 1/1250s - f/6.5
Filters: Baader AstroSolar Safety Film
Time: 2014-03-23 08:57 KST
Location: Suwon, Korea
Base photo: 32 photos stacked with RegiStax 6.1.0.8 (08:57:10 - 08:57:24)
Animation: 5 photos (08:57:16.8 - 08:57.18.5)