In our post on How to Successfully Photograph Star Trails, we discussed how to capture the stars: what equipment is needed, ideal location and set up, as well as camera settings. After following those steps, that leaves you with an SD card of 200 beautiful star pictures. Now, we will combine these images so that you will actually be able to see the earth’s rotation during this time.
The first thing you will want to do is edit your pictures in Lightroom or Photoshop, manually or using presets or actions for consistency and to save time . I will show you how I used Lightroom to efficiently edit these pictures (it took approximately 1 hour).
As you can see in the picture below, I adjusted the Tint (+65), Exposure (+3.50) and Highlights (+10). These are just recommendations – you can adjust as you like. Now, 200 pictures is a lot to edit, so you could use the Sync feature to apply these settings to all of your pictures, but I don’t recommend it. You really need to take the time to look at each one because the light changes throughout the night. For example, after the moon sets, it gets very dark. In that case, you would want to bump up the Exposure.
After you are satisfied with your images, it’s time to export them. Please note in the picture below, under “File Naming“, I chose “Custom Name – Original File Number“. This is helpful when importing them into your stacking program.
Once the files are exported, it’s time to open your program for stacking the images. I use a free program call StarStaX. You simply drag and drop your exported pictures into the program, and then set your preferences on the right. I keep it simple and leave it on “Gap Filling” and check the “Subtract Dark Images” check box.
Then click the “Start Processing” button (4th button in the upper left corner), and watch your images transform into one. This truly is an amazing process to watch. You can see the progress bar on the lower right. Once it’s complete, click the “Save” button (3rd button in the upper left corner).
Now all that’s left is to open your image and enjoy!