Leggi in ItalianoOn 24 July this year, while on holiday in Sardinia, I decided to try a small photographic experiment. For years, I have enjoyed watching the International Space Station (ISS) pass overhead, and I regularly use an app called ISS Detector, which tells me precisely when and where the station will be visible in the sky. This time, however, instead of simply watching it, I wanted to try photographing it.
And I decided to do so in a rather unusual way: handheld, without a tripod or any kind of tracking system.
For those who have never seen it, the International Space Station looks like a very bright point of light moving silently across the night sky. It travels surprisingly quickly, shining steadily rather than flashing like an aircraft. Sometimes it is even brighter than Venus.
That light does not come from headlights or any other artificial illumination. It is simply sunlight reflected by the station’s structure and its enormous solar panels. The ISS is approximately 109 metres long, roughly the length of a football pitch, and orbits about 400 kilometres above the Earth’s surface at a speed of around 28,000 kilometres per hour. An extraordinary object which, seen from the ground, becomes a tiny point of light.
That evening, I picked up my Canon EOS R5 with the RF 100–500 mm telephoto lens and decided to try a few shots at the maximum focal length. The main challenge was focusing. Getting a sharp focus on a tiny, rapidly moving point of light at 500 mm is far from easy.
So I used Venus, which was about to set, as my reference point. I focused on the planet and then switched off autofocus, preventing the camera from continually trying to readjust the focus as the station passed overhead.
I set the shutter speed to 1/500 of a second and the aperture to f/11. It was a fairly demanding compromise, considering the 500 mm focal length, the need to follow the subject handheld, and the challenge of freezing its movement. All that remained was to wait for the time indicated by the app.
When the ISS appeared, I tried to follow it through the viewfinder and took about ten photographs.
The whole transit lasted only a few minutes. To the naked eye, that little dot still looks like a simple point of light. But with a sufficiently powerful telephoto lens, it is possible to make out something of its structure, although the result depends on several factors: distance, atmospheric conditions, focusing accuracy and the inevitable movements of a handheld camera.
One of the shots looked particularly interesting. The original image had some digital noise and chromatic aberration, but it also contained details that seemed worth trying to recover.
So I tried another experiment: I gave the photograph to ChatGPT and asked it to increase the contrast and reduce the noise.
The result is what you can see here.
Of course, using artificial intelligence to process a photograph requires a certain degree of caution. Improving contrast and reducing noise is one thing; reconstructing or inventing details that the camera sensor never actually captured is quite another. That is why I regard the processed image as an interesting visual result, without automatically assuming that every visible detail corresponds to the station’s actual structure.
In any case, the station’s structure is already clearly recognisable in the original photograph, without any retouching or AI processing, and the solar panels are plainly visible.
Beyond the photographic result itself, what struck me most was having managed to capture, with an ordinary handheld camera, something hundreds of kilometres above our heads, travelling at almost eight kilometres per second.
There is also something else that continues to fascinate me whenever I watch the ISS. That little point of light is not a star, a planet or a natural phenomenon. It is a laboratory built by human beings, continuously inhabited since November 2000, and the product of scientific and technological cooperation between several countries. While we watch it cross the sky in just a few minutes, there are people up there working, conducting experiments and watching the Sun rise and set roughly sixteen times a day.
And to think that, on that evening in Sardinia, it all started with a simple notification on my phone. 🙂
For anyone interested in observing the ISS, in addition to ISS Detector, NASA provides its official Spot the Station service, which gives the times and trajectories of visible passes. More information about the station’s dimensions and technical characteristics can also be found on NASA’s ISS facts and figures page.