star trails

August 23/24, 2011 Star Trails

I took this photo tonight.  I used the same technique as I did in the previous post.  This one is about a 50 minute one.  For some reason my SLR powers off after about that long.  I will need to find out how to turn that off before making longer ones.

[singlepic id=2046 w=500 h=300 float=center]

Posted by Chad Dotson in Photography, 0 comments

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 in Photography, 0 comments