A Finnish astrophotographer has published a composite mosaic photo of the Milky Way with a resolution of 1.7 gigapixels. It has taken almost twelve years to create this high resolution photo.
JP has Metsävainio his picture and all individual admissions on astrophotography blog published. The total shutter speed was approximately 1250 hours and the photos were taken between 2009 and 2021. The final stitched photo is 100,000 pixels wide and is made up of 234 individual mosaics or panels, then joined together. This is a technique that is often used for panoramas, including astrophotography.
Some objects had a slower shutter speed than others, because otherwise, it was difficult to capture very dark objects properly. The colors come from the different elements, where green stands for hydrogen, red for sulfur, and blue for oxygen. About twenty million stars are visible in the photo with the end result.
There are a number of reasons why Metsavainio has taken so long on this project. The size of the photo is the most obvious reason. But another reason is the fact that he first regarded the individual elements of the photo as individual compositions and wanted to publish them as independent works of art. “This resulted in a complex image set with overlaps, with many areas between and around the frames not being photographed,” he says. Later he shot the missing data after all. This mainly concerns the less interesting parts without nebulae, such as the California nebula .
Metsavainio used the necessary equipment to get the picture and things changed over the years as well. For example, he used a Meade LX200 GPS 12 “telescope in combination with a QHY9 astro camera and a Canon EF 200mm f / 1.8 lens until 2014. After 2014, that was exchanged for another combination. For the recordings he used his own observatory. and the post-processing, such as linking the mosaics together, he did with Photoshop.