Comet Mode Star Trails

Photographing star trails is not as demanding as photographing the Milky Way because lower exposure is enough to capture the stars. However, star trails photography is time consuming since it relies on earth’s rotation to make stars move and longer trails may take up the entire night. There are 2 ways to photograph star trails. First method is called bulb mode, it is usually found in most DSLRs/mirrorless, what it does is it allows photographers to take a picture with their desired shutter time until they stop it but this mode is not available for smartphones (yet). Some smartphones or third party apps offer some sort of light painting mode, it would create similar effect but the output will be in JPEG which limits post-processing editing and comet mode star trails cannot be done with this method. Another method is image stacking with StarStaX application. More processing steps will be needed with this method and it gives flexibility to customize our desired result.

  1. Take series of pictures on tripod. Time interval between each shot should be similar. 
  2. Open all the images in StarStax.
  3. Click on the preferences icon on the right, it allows us to customize the result.
    • blending mode – Gap Filling, and there will be a Comet Mode check box (by checking comet mode, the length of star trails can be customized).
  4. Edit -> Start Processing

Result of star trails photo without comet mode checked. It is created with 79 frames (30second, ISO 1000, Daylight White balance for each shot) for about 45 minutes.

And with Comet Mode checked

Another Comet mode Star Trails.