Music: Stars by Rivers
(Attention Photographers: If you’re interested in “stacking” photos, simply use this action as described and select one of the final photos in the series, such as the one below. Also note that this was made using a 6 megapixel point-and-shoot camera, so your photos will probably look better.)
Can you find the North Star? I found the Big Dipper and Cassiopea and then just tried to point my lens in the right direction. I got lucky because I almost edged out my focal point. I find it amazing how little the North Star moves.
Why I Made this Action
Last week I posted a video of stars crossing the night sky to show the benefits of post production dark frame subtraction. This week’s video uses similar photos and a simple action I made using Photoshop CS3. This is my first time posting a Photoshop action, so I’d appreciate any feedback. The small gaps in the trails come from a short delay between photographs.
I came up with this technique after watching jcmegabyte’s star trails videos on Youtube. His videos are better than mine but I hope to refine my star trails in the future. Notice the small patch of purple in the upper-left corner that’s indicative of post production DFS. Without this post editing, his star trails would pulse instead of being constant.
My Photoshop action didn’t take long to make and is very simple, so you might want to edit it until you’re happy with the results. It features a slow fade-away because I liked the result better than persistent lines. You can see both types of trails in jcmegabyte’s videos.
Install the File
To begin, download the file to anywhere on your hard drive. Run Photoshop and open the actions box. When you click on the drop-down menu within the actions box, you should see an option to load an action. Click this and find the star trails action.
Process Your Photos
Copy your stars photographs into a new folder. This isn’t completely necessary, but I find it helps in case I accidentally process the original photos. Open the first photo in Photoshop. Select all, copy, and then close the photo (Ctrl+A,Ctrl+C, Ctrl+W). With this first file in memory, you can begin batching your photos.
In Photoshop, select “File,” “Automate,” and “Batch…” Find your stars folder and pick the star trails action. Click “Ok” and then go make a sandwich. Because this is a simple action, it shouldn’t take too long to finish. You can open your output folder while you wait if you want to make sure the action is working. Your first photo should look the same but the subsequent ones should feature growing light trails. Now turn the photos into a video as you would normally.
I’m hoping to use this same action to create other kinds of trail videos. I’ll post the results if anything turns out. Good luck!
Update: Erik Røstad made a much better video than mine using this script. Good job! http://www.flickr.com/photos/12328282@N04/4869251405/
I’ve also used this script for my video of planes landing at SFO.