Star trails have become a very popular photography subject, especially with the high ISO performance offered by some cameras over the last few years, but few will have the opportunity of creating them from such unimpeded views as the International Space Station.
Don Pettit is one of those few, stacking short exposures of the stars to produce some amazing star trail images, which also include the earth.
About these images, Pettit writes…
My star trail images are made by taking a time exposure of about 10 to 15 minutes. However, with modern digital cameras, 30 seconds is about the longest exposure possible, due to electronic detector noise effectively snowing out the image.
To achieve the longer exposures I do what many amateur astronomers do. I take multiple 30-second exposures, then ‘stack’ them using imaging software, thus producing the longer exposure.
To create star trails on Earth, one simply needs to point their camera to the skies and let the planet do the rotating for us. For those aboard the ISS, travelling at 17,000mph and circumnavigating the globe about once every 90 minutes, the techniques and results can be somewhat different.
With some of them might look like something pulled out of a scene from TRON, it definitely gives star trail photography an interesting new perspective.