Yesterday, I posted a short video I took of the ISS passing over Ottawa this past Tuesday evening, so I thought I’d post a copy of long exposure photos that I took.
I used my digital Canon Rebel on a tripod that I sat on the roof of my SUV. Generally, I had the ISO set to 1600, stopped the lens down to about f/20 and manually selected a 30 second exposure. The autofocus was turned off and I manually set the focus to ~infinity and confirmed it the stars were in focus with some test shots. I have a small wireless remote that I used to trigger the shutter. To avoid condensation problems, I set things up about half an hour before the pass to allow the camera to cool down.
This is a 30-second exposure taken near the maximum elevation of the pass, looking to the southwest. One problem with long exposures and digital cameras is that the sensors can be saturated, making it hard or impossible to retrieve the information. Fortunately, I didn’t have this problem and a little processing made the trail stand out nicely. In real life, both the shuttle and ISS were quite bright relative to everything else in the sky.
The second photo is the unprocessed version of the third image. If you look closely, you can see the faint trail about a third of the way up from the bottom, below the bright star in the middle of the image. If you look very closely, you’ll see a bright dot at the left end of the trail. This dot is the International Space Station.
Here is the enhanced version of the photo above: