The "Startrails"-application

With modern digital cameras is it relatively easy to get decent startrail-images. Instead of taking one long exposure one can take many shorter exposures and combine them in Photoshop using layers in "lighten"-modus.
The big advantage is that the background heaven will stay as dark as on the single exposures.

My procedure: When visual observing with my 12" dobsonion style Newton telescope I usually can't resist taking some startrails. I put my Canon 10D on a tripod with a wide angle lens at maximum aperture.  Camera is set to ISO 400 at an exposure time of 30s.
To start the exposures I put the camera in "continous drive"-mode and lock the cable release. Usually the camera is capable to take 3 frames a second, now however it takes one frame every 30 seconds ;-)

So as you can see taking the images is easy, stacking them (usually about 200 to 300 images) in Photoshop is not too much fun.....

This is why I decided to develop the "Startrails.exe"

What does it do?

You can load the Images and optionally some dark.frames (will be averaged and subtracted automatically if exist).
If there are some images you don’t want you can uncheck them.
Zooming into the images is done with the mouse-wheel
Optionally you can average some of the images to get a better signal to noise ratio for the sky-background or the foreground. This averaged image is brightend internally and at the end of the processing blended in "lighten"-mode into the resulting image

The resulting image can be saved in Jpeg,TIFF or BMP format

Another feature is the creation of a time-lapse movie as an "AVI"-file
Of course this feature can be used to create any time lapse movie, not only starmovies..

System requirements:

As it is developed in C# you need the Microsoft .NET framework installed. If you use Windows XP, Win 2000 or Windows 7 with automatic updates enabled the .NET framework should be installed.
To download the latest framework use this Link

               Microsoft .NET Framework Version 4 Redistributable Package

If you are interested in using Startrails you can download it here:

Donations are kindly accepted and will help towards further development

29th July, 2013:New: Falling stars!
Russian translation, thanks go to Igor Sokalski !
Italian translation, thanks go to Matteo Consolati!
Clear skies, Achim

11th February, 2013: Fixed a Windows 8 bug (menus not working)
Turkish translation, thanks go to Gorkem Koray Oz!
Bulgarian translation, thanks go to Mihael Yovchev!
Portuguese translation, thanks go to Nuno Santos!
Clear skies, Achim

5th November, 2012: French Version!
Thanks go to Ulrich Schüly for the translation!
Clear skies, Achim

29th August, 2012: Version 2.1!
Spanish version (Thanks go to Montenegro Marcelo Fabian from Argentinia for the translation!)
New option to create a series of images, each showing the growing trails (What you see when the startrail-image is created. After each blend the resuling image is saved and can afterwards be used to create an animation showing the trails growing... Clear skies, Achim

1th May, 2012: Version 2.0 is here!
Main feature: closing the gaps! Clear skies, Achim

18th March, 2012: Dear friends of Startrails, I am really overwhelmed how many people are interested in the software. As you can see in the history log below, last update was back in 2005.
But now I am really encouraged to make a major update.
Main features will be: closing gaps, better performance, new video module (one that really works) with "growing trails".
So maybe you want to come back and have a look after a while (some weeks)...
Clear skies, Achim

Feel free to share your images at Facebook:

Or visit my blog Macrosphaere

Two great sites with startrails-tutorials:
Duane Cassone:
Floris van Breugel:
Rubbing Pixels


02/11/2013: Version 2.3

    "Falling stars"

    Russian Version

    Italian Version

02/11/2013: Version 2.2

    Win 8 bug fixed (menus not working)

    Turkish Version

    Bulgarian Version

    Portuguese Version

29/08/2012: Version 2.1

    Spanish Version

    Crescent (growing) trails

05/01/2012: Version 2.0

    Closing the gaps!

05/30/2005: Version 1.1

    - minor changes


    - memory improvements

    - fixed problems with averaging

    - processing large files for AVIs

    - statusbar improved

    - ESC-key to abort processing

    - fixed problem when starting per desktop link

    - scaling to screen size per default


    - fixed memory problem

    - added progress bar

Just unzip it to a place you want and start the exe....

Disclaimer: This software is free and you can use it as it is. If you find any bugs please report them to me, I will try to fix them when I find the time. Any comments are welcome and I would be happy if you send me some images you created (please no videos ;-)