How to photograph star trails
Fancy some astrophotography? Trying to photograph star trails is a great place to start. Star trails are long exposure images that show the movement of stars in the night sky and create interesting and visually captivating images. Like any astrophotography, they require some planning and technical know-how to function well, but the technique behind them is relatively straightforward. Our guide will tell you everything you need to know to get the perfect star trail footage. For those who are very enthusiastic, you can check out more tips in our beginner’s guide to astrophotography.
What is the most important piece of equipment for star trail photography? The humble tripod! A good, sturdy tripod is essential. You will be shooting long exposures and you need a tripod to support the weight of your camera / lens, while still being stable in windy conditions. You can’t go wrong with a Manfrotto tripod for strength, although the aluminum versions are considerably heavier (but cheaper!) than the carbon fiber equivalents. The Peak Design Tripod with integrated ball head is the cleanest and smallest tripod on the market, but you may find its lack of height a bit limiting.
For the highest quality star trail images, a full frame camera is your friend, but you’ll get good quality images with most mid-range APS-C and micro four-thirds sensors. Olympus cameras come with an amazing feature called “Live Composite” which means that you can create your star trail images at the camera by building up the shot gradually – the E-M1 Mk III is a particular favorite. Our guide to DSLR vs mirrorless camera for astrophotography will help you find a camera that’s right for you.
If you want awesome star trails, you’ll need a wide-angle lens – we really like the Canon EF 16-35mm f / 2.8L III USM lens. Typical focal lengths range from 10mm to 35mm, depending on how much landscape and sky you want to capture in your shot. Of course, you can also shoot with a telephoto lens for short exposure times, but you won’t capture such long trails or such a large part of the sky. Your lens should have a large aperture of around f2.8 – f4; this is essential to let as much light as possible in your image. We always recommend that you spend your money on a lens rather than a new camera – a good glass makes your image.
Finally, we strongly recommend that you invest in an intervalometer. This is a programmable remote shutter release that allows you to avoid camera shake, adjust the exposure time, the time interval between each shot and the total number of photos you take. you want to take. The Canon TC-80N3 is the best in the market, but Yongnuo makes cheaper ones that are great for starting out.
It also goes without saying that you’ll need good quality memory cards, extra batteries (kept in your pockets to keep them warm), and a headlamp for focus and general safety.
As with all astrophotography, you want to be as far away from light pollution as possible. You can photograph star trails in the middle of a city, but there won’t be as many stars visible. A new moon also removes fewer stars from the sky, and you’ll want a clear night with no thick cloud cover. If you want to capture the full effect of the “rotating sky” in the northern hemisphere, you will need to shoot north at Polaris. An application like Photopills will help you plan your shot and we always recommend visiting your location in daylight to plan where you are going to shoot.
Take your picture
In the good old days of cinema, we took pictures of star trails by simply leaving the shutter open for a long time. The problem with digital technology is that digital camera sensors can get very hot if left open for a long time. So it’s best to take lots of shorter exposure photos and then stack them in post-production. For best results, you will need to take about 50 to 100 exposures of about 30 seconds each. If that seems too difficult, start by taking about 10-20 exposures of about 3 minutes instead.
Always shoot in RAW, so you have all the post-production options, and be sure to turn off camera noise reduction – if you leave it on, you’ll end up with little holes in your tracks ( you might find our tips on how to reduce noise in astrophotography helpful). Use your wide angle lens at its maximum aperture (ideally f2.8 – f4) and shoot at around ISO 800 to start (you may need to increase your ISO if you don’t get enough light in your camera). Set your lens to manual focus and pre-focus it to infinity or point a torch at something about 20m away, focus using autofocus, then return to manual mode. Be sure to take a few test shots before you start and zoom in to verify your focus is sharp.
Composition is essential with the images of star trails. You need a foreground subject to locate your star trails. Hills, mountains, trees, buildings – anything that frames your sky and draws the viewer into the picture is ideal. Once you’re ready to start taking photos, make sure you have a new battery in your camera, set up your interval, and start taking photos. (You can shoot with a normal remote shutter release, but you’ll have to manually set up your schedules, etc.)
Editing star trail images
It’s hard to beat Adobe photoshop for working with star trail images. Open your selected images in Camera Raw, select your first image and edit it as you like. Then select all the images, right click and select Develop Settings> Previous Conversion. This will sync your edit across all frames.
With the photographs still selected, click Tools> Photoshop> Load Files into Photoshop Layers. Photos will now be loaded as a single image with multiple layers. Starting with the bottom layer (make this layer only visible by clicking the eye icon on every other layer), select Layer Blend Options, then Lighten. As you repeat this for each layer, you will start to see more and more star trails appear. If there are any streaks that you don’t want to appear, you can just use the brush tool and paint them black. It will make them disappear. Finally, flatten your image.
If you don’t have Photoshop, StarStax is great free software that will process a star trail image in about five minutes.
Star trails are a great way to dip your toe in the water of astrophotography and the results always have the “wow” factor. Why not go out tonight and start experimenting?