If you’ve ever seen images of deep space objects like nebulae and galaxies when browsing through the Internet today, you might have wondered why they look the way they do. I mean, it’s not that hard to point the camera up and take a picture of the night sky. But there’s more to it than that.
Anyone can take pictures of the stars or even the Milky Way. But most people who are just getting into the hobby tend to rely on the noise performance of their cameras to take a picture of the stars that are perhaps an interesting foreground. But have you ever thought about drinking more?
In this video by astrophysicist Nico Carver, who follows Nebula Photos on YouTube, the term “Image Stacking” completely unravels when he shows the process of taking multiple sub-exposures and combining them into one photo. Nico carefully explains the math behind why taking multiple subexposures and stacking them is better than just taking a single long exposure. We were able to watch the process and compare it along the way, from one to four images, all the way up to 16 and 64, and finally 256 and 1024 images, respectively. He shows cropped comparisons between different sets of images to reveal the process further, highlighting an increase in detail and a decrease in noise with each successive set.
I’ve been passionate about astrophotography for years now, but I’ve never really gone through the process myself or taken the time to fully understand the math behind it. However, I was really surprised at the fact that he completed this mission without a star tracking device. Now, to be fair, he used Canon EOS Ra, is an astrologically modified camera. But the only advantage that particular camera gives him is the ability to use fewer photos, since Ra is more sensitive to near-infrared light. Also, anyone can use this video to understand more about image stacking process.
