Upon return from my recent high-altitude trek to Pakistan’s K2 Basecamp, I was flooded with requests and questions on how I made this particular image:

This kind of image is called a star trail. As the name suggests, it’s a long exposure photograph of the stars in the universe rotating in relation to Earth.

At blue hour, I plopped one camera on a tripod, then took out another camera to photograph the mountains and went to bed, leaving that first camera out all night. When I got home, I slapped all the images from both cameras into a single image. If we’re strictly counting the time I spent behind the cameras and computer, that value would be best expressed in minutes. In some ways, astro can be one of the more effortless forms of photography. Especially for star trails.

Okay, I’ve wasted enough of your time. But let me first waste more and preface this with these disclaimers:

For me, the image usually starts one of two ways: with a plan, or a vibe. I can’t tell you how the “vibes” happen, but I can tell you how I plan for an image. Basically, I look for something cool and see if there’s any way to make a cool image from it. In this case, K2. But always, I start here, with the following tools:

As I was inspecting the trek’s route, I noticed that Concordia, the campsite from which 4 of Pakistan’s 8,000m mountains can be accessed, was south of K2. Using Google Earth, Gaia, and Plan It Pro, K2’s peak lined up almost exactly with the North Star when viewed from Concordia. With this, I knew the image was viable and the only thing I had left to do was get all my cameras there, and hope for clear skies.

Now, I really like my photos to have a bunch of different uses, so I do my star trails a little differently. It may appear illogical, but I capture star trails by time-lapses and don’t actually want the trails in my photos when I create my star trail images. Because with the thousand or so images I get from running the time-lapses, I get at minimum, four pieces of media:

Two different photos and two different time-lapse videos from just one night of imaging, all while I’m sound asleep in my tent? Now that’s my kinda deal.

As far as settings go, it’ll depend on your focal length. Use a star trail calculator like ones found in PhotoPills, just always make sure to perform test shots and check for trails. One of the most annoying mistakes you could possibly make is set up your time-lapse, go to bed, and wake up with 3,000 out of focus or poorly exposed photos. Ask me how I know haha.



The exact settings will heavily depend on ambient light pollution, focal length, camera megapixels, max lens aperture, but I typically stick to around 14-24mm, 5-12s, f/1.4-2.8, ISO 2500-6400. The time-lapse interval depends, but this time on how much battery life and storage space I have and how long I want the resulting time-lapse video to last. Usually I try for 1s interval to get as many photos as I can, as the more the better. 



Important thing to note here is that I slightly underexpose the star images, and that’s because to get the most color out of the final star trail image, you want to avoid blowing out the highlights of as many stars as possible.

With my other camera, I photograph the foregrounds. It’s a lot less work here, just make sure you’re in focus and go for a 30s exposure and crank the ISO until unnecessary. I typically aim to have darker foregrounds just to make things look more natural, but still usually take these towards the end of blue hour to make sure I can see and focus on them properly.

Once you’re back in front of the computer, I first take the time-lapse images, apply batch edits to the exposure, convert them to TIFFs, then plop them into StarStax. I do my edits and conversion in Capture One, but Bridge + ACR, Lightroom, and other RAW editing programs should be able to handle these tasks as well.

Then, I render the images. I always use these settings:

but sometimes I’ll try running the stack in reverse. Sometimes it looks better that way, just try it out. Sometimes you get all the way to the end and find out you don’t like how it looks after all, and have to start again. It’s all normal and part of the process.

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STEP FIVE:

Edit the foreground image to taste as you normally would. I did mine in Capture One. I also like to keep the foregrounds underexposed to keep it more natural looking and match it with the sky a bit more.

Bring the stacked & blended sky image, and the edited foreground image into your layer editor of choice. I use Affinity Photo 2, but Photoshop or the new Affinity will work just as well. At this point, we’ve rendered the sky image, but haven’t edited it. We’ll do that now.

Typically I add about 10% saturation and then duplicate the layer with 10% opacity. Then I just keep duplicating it until I’m happy with the saturation.

To get the actual trails smooth and perfect, I add a radial blur to the layer, just enough to cover the gaps between exposures and possible cloud interference.

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STEP SEVEN:

Blend the two images together. It’s fairly straight forward, cut the sky out of the foreground layer, cut the foreground out of the sky layer, align the two accordingly. I typically like to have the sky layer behind the foreground layer, then feather the edges of the foreground layer to blend it with the sky a bit more, again to taste and usually extremely minor.

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And boom. There’s your image.

If you’ve got any further questions, please feel free to email me or DM me on social media! Always happy to help.

As always, thank you so much for reading. I hope you enjoyed, do consider subscribing if you’re not already, and have a good one!

PS. do forgive how poorly written and explained this guide is. I tend to not stick to any particular set of rules as each photo has a slightly different way of going about things, but this is generally what I do to get the best results for what I’m after. I’ll be making an even more in-depth video tutorial of this image in the future, but for now, have a look at this silly reel I made in the past on a similar star trail image. The process is largely the same!