Creating a Startrail Image
This image was my very first star trail image taken at Lake Powell on Valentines Day when me and Tiffany were camping by the lake. The landscape is lit up from moonlight which gives it a very different effect.
A few people asked me recently how I created my Startrail image which is below. It's easier than you think and all you really need is some time and a sturdy tripod. Scroll down to see my workflow and how to process the images together.
First your going to need to find Polaris assuming you are in the northern hemisphere. First, find the Big Dipper, and then from the end of the scoop, follow an imaginary line away from the dipper, not parallel to it and about a palms width and you'll find a fairly bright star. That is the North Star commonly known as Polaris. Now, if your in the Southern Hemisphere you'll need to find Ocatans which is between the Magellanic Clouds and the Carina Nebula. (below)
Northern Hemisphere:
Big Dipper in Northern Sky. See how the edge of the cup points towards Polaris?
Southern Hemisphere:
Rough approximation of Octans as seen from Mount Cook National Park in New Zealand. (Southern Hemisphere)
Once you have found the pole in your hemisphere you need to set your tripod up and make a few test exposures to see what is best for the lighting conditions your in. What usually works for me if I'm in a very dark location and the moon isn't up is: 100 seconds, ISO 400, and f5 or so. If the moon is up and there is some light pollution you will want to do shorter exposures. For example ISO800, f4, and 40 seconds.
Once you've made some test shots and everything is looking properly exposed lock down your tripod so it doesn't move at all for the next couple hours. Set your camera on timer mode and take at least 100 pictures at the settings mentioned above. Once it starts don't touch it and don't interrupt it or you will have gaps in your trails.
A single frame on the left, notice how only the stars at the edges seem to show the tiniest movement. On the right is the outcome of stacking many images together.
The images that make up this stack were taken at: 40mm, f2.8, ISO800 and 30 seconds.
Now that you've got the images captured your probably wondering what to do with all these fragmented pieces. A free program called StarStaX works wonders but you can process them together just as well in Photoshop.
You'll need to set the either program to the "Lighten" blend mode and then start opening each file and adding it to your stack. Every time a file is added your trails should grow by the smallest amount. After adding up so many images you get the effect of the whole sky blurring together as it rotates.
Starstax program after adding up all images into one stack.
After you have the effect you want you'll need to flatten your images together into one single file so that it can be shared, printed or worked on again in another program. I usually play with the curves and color balance in Lightroom or photoshop to get the effect I want. Now wasn't that easier than you thought?
Final image from stack after minor editing in Lightroom. Captured at Sunset Crater National Monument after midnight.
Any questions please comment below and share if you found this helpful. Later this summer I will be offering Astrophotography classes around Northern Arizona so if you are interested contact me above as the limited space will go fast.