I’m very excited to share with you this Animated Star Trails GIF I created.
Those of you who own a copy of the larue.photo 2018 Fine Art Wall Calendar may recognize this weeks image as “August”. The still version seen below anyway. I made an animated version and I’d like to tell you about how I captured it, and share my post-processing techniques.
To create this series I captured 372 still images over the course of 4 hours 4 minutes and 33 seconds. Each image was a 25 second exposure, except 1 image at 30 seconds for the foreground.
When I shot the beginning of the sequence, the waxing gibbous moon was getting ready to set. This gave me a deep golden light with long shadows to work with. With that light I was able to capture the images necessary to build the foreground layer. Shortly thereafter the moon set, causing the foreground and sky to go dark, but the stars continued shining brightly, allowing me to continue capturing their trails.
Below is the result of stacking 372 images into a single composite image.
Creating Animated Star Trails
Creating the animated star trails GIF seen at the top of this page was a rather involving manual process.
First, I made adjustments to all the RAW images using either Lightroom or Bridge. Then I exported all images at 72dpi and 1280px wide. Since my final output for this project would be screen, there was no sense in working with large files.
Next, I loaded all 372 images in Photoshop as a stack. And finally it was time for the labor intensive portion. I started with just one layer visible, the first shot captured, and exported a JPEG. Then I turned on the next layer and set the blend mode to lighten. The lighten blend mode allows the brighter parts to shine through while the darker parts are ignored.
In this way each subsequent image shows the position of the stars in each previous image. By exporting each new image this way I was able to create a series of frames in which the star trail grows.
Once I created all the frames I loaded them all in Photoshop as a stack and made frames from layers. Exporting a GIF using all the frames would have resulted in a very long and slow GIF, with a very large file size. Instead I used only every 20th frame to create a 2 second animation which grows, then reverses and shrinks back a single star.
I’m certain there is a simpler way to accomplish this same effect. Something like a video editing program that can utilize the lighten blend mode. Tell me in the comments if you know an easier way.
So, what did you think? Did I explain my process clearly? Is there an easier way to do this that I can employ next time? Tell me in the comments. Connect with me on Facebook and Twitter to stay informed of my most recent updates.