Photo Courtesy of Steve MacKay
Excerpt from Steve MacKay's Blog: http://www.stevemackayphotography.com/section363141.html
While learning tips on night photography and star trails on the internet I stumbled upon an application
called "startrails.exe", this software allows a photographer to take multiple exposures (several hundred if
necessary) and blend/stack them together, the image on the top is made up of approx 40 different 1min
exposures blended together in startrails.exe.
Each individual shot (out of the 40) shows the stars as the human eye sees them (small round dots), but
after the 40 minutes the earth has rotated so much around it's axis that the stars are in slightly different
positions in all the shots, the software purely joins up all the stars to create the star trails effect.
Of course you could take a single 40 minute exposure to get the same result....the problem is that (in my
part of the world at least) you will have a lot of light pollution which can ruin the shot, or you will have to
select a lower iso and or narrow aperture that will render the star trails much fainter.
Below I will give some tips on how to take the shots and use the software, plus some pro's and con's (of
which there are both). also some alternative techniques to create the same effect. To read the entire
article click on this link: http://www.stevemackayphotography.com/section363141.html and then go to the Star
Trails article. I hope you will find this article as fascinating as I did, and that you will be able to attempt
your own shots!