Astrophotography can be a very rewarding pursuit. It’s a unique blend of art and science. The science is in the capturing of the image, while the art is in how the images are processed. The allure of photographing the night sky draws both professional photographers and amateurs. How many of us have been wowed by the images taken by the Hubble Telescope or the new James Webb Telescope?
The International Space Station (ISS) and satellites are unique celestial objects, since unlike most nighttime objects they move in real-time across the sky. Orbiting Earth, the ISS offers a unique subject for astrophotographers. It’s not just about stars and planets; the ISS represents humanity’s aspirations and technical accomplishments — an outpost in the sky that reflects our quest for knowledge.
In recent years astrophotography has leapt forward with advances in digital imaging technology. Today, amateur photographers have access to tools and equipment that were once limited to professionals. In the 25 years in which I have been enjoying this hobby, I have witnessed incredible advances that can make capturing celestial objects almost effortless. There were many a night years ago that I spent struggling with primitive (by today’s standards) equipment, only to have to scrap an entire night’s work because of poor results. Today, with a modest investment and dedication, capturing the ISS as it sails overhead is accessible to almost anyone.
Because the ISS moves in real-time, timing is essential, and many websites and tools can give precise tracking details for your location. But the results are spectacular, producing photographs that not only awe and inspire but become a testament to human ingenuity. With good planning, it is even possible to frame the ISS as it passes in front of the moon (or sun with the proper filters). In the following sections, I’ll share the essential gear you’ll need. This isn’t just about the camera and tripod; you’ll see that preparing to photograph the ISS is as much about the preparation as it is about the shoot itself.
Equipment Essentials: Gearing Up to Photograph the ISS
When you decide to capture the grandeur of the International Space Station as it sails across the night sky, the success of your endeavor largely depends on the equipment you use.
I recommend a tripod or a mount if using a telescope. Most modern telescope mounts can’t track the path of the ISS because it doesn’t follow the ecliptic like other celestial objects. And it is traveling at over 17,000 mph. An altazimuth mount like the Dobsonian mount offers the most flexibility for moving the mount axis in both altitude and azimuth relatively easily and quickly. Long focal lengths can be used to capture a spectacular magnified image, but because the field of view is so small, it is very easy to miss your opportunity. A shorter focal length will give a larger field of view and less magnification, but the window of opportunity is bigger. In the next section, I mention two websites you can use to position the camera or telescope to where the ISS is expected to rise above the horizon. Or point the camera or scope toward the sun (with proper filters) or moon and wait for the right predicted moment. You can use a finder scope or binoculars to do your initial spotting as it comes into view. If you are adventurous and have a steady hand, you can attempt to follow the path of the ISS with your camera and take multiple snapshots as it passes overhead. From one horizon to the opposite, it only takes a minute or so for the ISS to pass overhead depending on your latitude.
A DSLR or mirrorless digital camera is ideal. A full-frame sensor will give a larger field of view at the expense of less magnification. You can choose to take still images, or you can use video mode to capture the ISS as it moves across the predicted path. For those using telescopes, depending on your camera sensor, focal lengths of 300-700 will give a decent field of view. If you are going for higher magnification and not worried about framing the moon or sun, 1000 mm or more would give a smaller field of view (and better magnification), but precise aiming is much more important.
An often-overlooked piece of equipment is the remote shutter release or an intervalometer. This device allows you to take photos without touching the camera, minimizing vibration and enabling you to capture a series of images over time – a technique we’ll explore more in the next section.
Techniques and Timing: Mastering the Art of ISS Astrophotography
Let’s start with planning. Many websites can give you details about the location of the ISS. The ISS orbits our planet approximately every 90 minutes, but not every pass is visible from a single location. I have found heavens-above.com to be quite useful in determining when the ISS will pass over your exact location. First, select your precise location using an interactive map. Once your location is entered, look for “10-day predictions for satellites of special interest” and then select ISS. This will give you details about upcoming flyovers for your location. You can then predict where to look on a given night. If you are interested in capturing the ISS as it passes in front of the sun or moon, try transit-finder.com
Capturing an image of the International Space Station as it streaks across the sky is no easy task. It involves a combination of precise timing, proper technique, and, to some degree, good fortune.
Once you pinpoint the right moment, adjust your camera settings accordingly. For shooting something as bright and fast-moving as the ISS, if you are using a camera and lens (instead of a telescope), set a wide aperture to let in as much light as possible, and a high ISO for sensitivity. However, be mindful of the noise levels. Experiment with the night sky before you try this to get just the right settings.
Often, long exposure is used to create those stunning trails as the ISS moves. But the key is to avoid overexposure. Start with an exposure time of around 20 to 30 seconds; you can adjust as needed.
Stacked imaging — a technique that combines multiple images of the ISS — can create a cleaner, more detailed final image. Capture several short exposures of the ISS and use stacking software to overlay the images. Ideally, the shots are short enough (fractions of a second) that there is no perceptible movement of the ISS. The ISS is one of the brightest objects in the night sky, so very short exposures are perfectly fine. Or you can take a video and select the best frames for stacking.
Focus is also critical. If your camera has a live-view mode, use it to zoom in on a bright star first and manually focus to ensure the sharpest image possible. If you are using a telescope, a Bahtinov mask is quite useful in obtaining perfect focus when pointed at a bright star.
Lastly, composing the shot can be tricky due to the speed of the ISS. You can point toward the horizon where the ISS will initially appear and frame it with foreground trees or mountains. Or point to the moon and wait for it to pass in front when that path is predicted.
Showcasing The Heavens: Sharing and Protecting Your ISS Images
You invested time, honed skills, and possibly braved chilly nights to capture the International Space Station sailing across the stars. Now you’re ready to share your work with the world. Social media platforms like Instagram and Twitter are popular stages where space enthusiasts eagerly await new cosmic views. Photography forums and dedicated astrophotography websites also offer spaces for you to display your images, receive feedback, and connect with peers. If you are really passionate, you can even start your own blog and build an audience.
Participating in online communities, such as astrophotography groups on Facebook or Reddit, can be fun. You’ll find camaraderie, support, and a channel for both learning and teaching. Exchanges within these communities often lead to learning about more advanced techniques and showcases featuring new equipment or software.
It’s exciting to share your images, but understanding the legalities of copyright is important. If you plan on commercializing your images, always watermark your work and be familiar with the terms of the platforms where you post, to ensure your copyright is protected. When you share online, you’re not just exposing your art—you’re bolstering your reputation as a photographer and contributing to a broader appreciation for the wonders of our universe. I wouldn’t worry too much about copyrights if you just want friends, family, and the astronomy community to enjoy the fruits of your work.
Lastly, by backing up high-resolution versions of your images and maintaining a well-organized archive, you safeguard your work against loss and ensure that it’s readily available for myriad uses: from prints to digital publications. This proactive measure ensures that your efforts today can inspire and be appreciated well into the future.
Remember, each photo of the ISS you take is more than just a snapshot; it’s a testament to human achievement. With each image shared, you’re doing more than displaying your skill—you’re helping to ignite curiosity and passion for space exploration in others.