How to Shoot Star Trails — PROMASTER BLOG

Shooting star trails is a fantastic way to capture the movement of the night sky and create some of the most unique astro images you’ll shoot. In this guide, we’ll dive into everything you need to know from gear and settings, to shooting techniques and post-processing.

Before we dive into things, let’s get an understanding of what star trails actually are. When you take an image of the night sky, you’ve most likely seen each star individually, representing a more “static” appearance of the sky. With star trails, we are overlaying dozens of star images on top of each other to demonstrate the movement of the stars and the sky overhead. It’s a testament to patience, but also a stunning method of implementing a sense of movement into a subject of photography that often focuses on stillness.

Now that we have an idea of what we’re aiming for, let’s break down the process into four separate phases: gear, planning, shooting, and processing.

Step One: Gear

Having reliable gear is crucial for any form of astrophotography, especially when it comes to images that we’ll be stacking.

Choosing the right lens for star trails can significantly impact your results. A wide-angle lens is ideal, as it captures more of the sky, allowing for longer, more dramatic star trails. Fast apertures like f/2.8 or wider will help gather as much light as possible, reducing the need for extremely high ISO settings and minimizing noise. If you want to include foreground elements, a focal length between 16mm and 24mm works well, creating a balanced composition that highlights both the landscape and the night sky without dealing with too much distortion.

Once we have our lens picked out, we need something to keep our camera still for 10+ seconds. For my astro work, I’m always going to rely on the Epoch Tripod for the aluminum weight and build quality of the legs as well as the four-way head that allows for extra fine-tuned adjustments. We cannot afford any movement while our camera sits for an extended period of time, so the sturdier our camera sits, the better off we are.

Beyond the tripod, you’ll want to check and see if your camera has a built-in intervalometer. If not, ProMaster has the exact tool you’ll need to add one to your setup. With their RF Timer Remote, you can set your interval and let your camera sit and fire as many shots as you need once you begin capturing images. The purpose for this is to be able to let our cameras shoot as many shots as we want without needing us to press the shutter, potentially bumping and blurring our shot.

Now if we’re going to capture dozens of shots that are processing a fair amount of data from long exposures, we’ll need storage options that can keep up with that. I’ve been using both the Rugged V60 SD Cards for some time now, and I’ve never once dealt with any backup with buffering images. They keep up with my shooting, and if you’re like me and shoot in the cold winter nights in Wisconsin, you’ll also be reassured that they’re made to hold up in frigid temps.

Going back to what I had mentioned about Epoch, I’ve also become a huge fan of L-Brackets. They’re sleek, rigid, and offer much better balance when shooting in a vertical orientation. Rather than having my camera off to the side of a tripod’s head, this allows me to rotate the camera itself and keep all the weight centered on top. (It also makes a great grip to hold onto when walking around, might I add!)

Step Two: Planning

Once we’re equipped with all of the tools we need to execute our shot, it’s time to plan for a night that will have optimal conditions. We’ll want to keep three main components in mind: wind, cloud cover, and moon phase.

Checking your local forecast the night leading up to your expedition is a perfect method to stay in the loop with conditions. The less wind you have, the better off you are for more stable shooting and still scenes. With cloud cover, well, we don’t want any. Keep an eye out for clear skies in the forecast, but also during the day. Oftentimes if you’ve had clear skies throughout the day, it’ll remain that way into the night. The one key element that can truly elevate the night sky for you, however, is the moon.
Resources like TimeAndDate are a perfect site to check in on to see what moon phase you’re dealing with. If you’re looking to light up your foreground, you can use a brighter moon phase, such as a waxing gibbous or even a full moon, to your advantage. If you want the darkest skies possible with the brightest stars, aim for a new moon, or a waning crescent. You may lose detail in the foreground, but if you find a scene that can work well as a silhouette, you’ll do just fine. I look for single trees, barns, or just pure flat fields that can allow the sky to do the heavy lifting.

Step Three: Shooting

Once you’ve found your spot and the weather agrees to cooperate, it’s time to start shooting!

When shooting, it’s preferred to use manual mode to have full control over your settings. Set your aperture wide open (e.g. f/2.8 or lower) to bring in as much light as possible. Start with an ISO between 800 and 1600, adjusting based on your camera’s noise performance and the brightness of the sky. If you’re in a very dark location, you can push the ISO higher, but in areas with some light pollution or the moon being out, keeping it lower will help reduce any glow. Turn off image stabilization (IBIS or lens IS) and set your focus to manual, using live view to zoom in on a bright star and fine-tune focus for maximum sharpness. For shutter speed, you have the freedom to go longer. I typically shoot at 20s per image, however some photographers set their camera to “bulb” mode and shoot 2-3 minute exposures at a time. Both methods work, but with more shots means you can customize your final product a bit more with how many images you want to stack.

Once the settings and composition are dialed in, use your RF Remote Timer (or the built-in interval timer) to take as many consecutive shots as you’d like. I typically shoot 50 at a time over the course of 30 minutes to a few hours. Since your camera will be working non-stop, keep an extra battery or two handy and use a Rugged SD card with more storage to ensure smooth operation without interruptions. After all of the shots have been gathered, it’s time to import them into Lightroom, make some adjustments, and polish things off in Photoshop.

Step Four: Processing

The first efforts we’ll make after importing everything into Lightroom is to make minor adjustments before stacking. Select the first image and adjust exposure, contrast, and white balance to achieve a balanced night sky without overexposing the highlights. You may need to lift shadows slightly to bring out foreground details while keeping the sky dark and natural. Apply noise reduction carefully—too much can blur the finer details in the stars. If you’re shooting in a slightly light-polluted area, consider using the Dehaze tool to deepen the night sky. Once you’re happy with the adjustments, sync the settings across all images in the sequence to maintain consistency. Then, export the files as high-quality JPEGs or TIFFs to bring them into Photoshop for stacking.

In Photoshop, go to File > Scripts > Load Files into Stack, select your images, and be sure to check “Attempt to Automatically Align”. Once loaded, select all layers except the base layer, and change their blending mode to “Lighten”. This makes the brightest parts of the image (the stars) visible while keeping the dark areas (foreground) intact. Finally, merge the layers, apply any final contrast and color tweaks using a Camera Raw Filter, and save your finished star trail!

Capturing star trails is a rewarding process that puts technical skill, patience, and creativity all to the test. From selecting the right gear, to dialing in your settings and perfecting the final image in post-processing, each step is a fun learning process to explore a new avenue of astrophotography. Best of luck in your hunt for dark and clear skies, and be sure to use #promasterphoto when sharing your work!