August 21, 2011 Star Trails

I took these photos last night with my Nikon D5000.  I set it to take repeated 30 second exposures.  I then overlaid the images using a command line bash script and Image Magick.  The first is about 25 minutes worth of photos, the second is about 50 minutes worth.

[singlepic id=2045 w=500 h=300 float=center]

[singlepic id=2044 w=500 h=300 float=center]

I started with a the first image as the “../temp.jpg” as listed below.  This could be a image from the series or a blank black image of the same size.  Then I ran the bash code below to generate the images.

$ ls *.jpg | while read a; do convert ../temp.jpg $a -gravity center -compose lighten -composite -format jpg ../temp.jpg; done;

Posted by Chad Dotson

A small town Computer Scientist / Software Engineer. Chad enjoys writing Python and JavaScript as well as tinkering with his Raspberry Pi and Arduino. When not programming, he enjoys Photography (especially lightning) and Sci-Fi.

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