The stock Samsung Camera app is very powerful, but you need to use Expert RAW to extract the maximum performance from the cameras of the best Samsung phones. It is like Pro mode on steroids, allowing you to capture RAW photos with multi-frame HDR. Samsung even added an Astrophotography mode to the app in October 2022. So far, this new feature was limited to the Galaxy S22 and S23 series. The Korean giant is now expanding the Astrophotography mode's availability to the Galaxy Z Fold 4 and Galaxy S21, its 2021 flagship smartphone lineup.
Post the latest Expert RAW update, you can use the app to capture the night sky on your Galaxy S21 or Z Fold 4 (via SamMobile). Do make sure your phone is running the April 2023 security patch, as that's also required for compatibility reasons. Samsung had previously revealed its plans to bring many Galaxy S23 camera features to older Galaxy flagships with the One UI 5.1 update.
With the Astrophotography mode in Expert RAW, you can capture the night sky by keeping the shutter open for as long as 10 minutes. There's a useful Sky guide mode as well that overlays the position of the stars and constellations on the viewfinder. Since the shutter remains open for an extended period of time, you must use a tripod or rest your phone against an object to ensure it is stable. This is not an issue on the Galaxy Z Fold 4, as you can take advantage of its built-in Flex mode to rest the camera at a certain angle.
If you don't see the Astrophotography mode on your Galaxy S21 or Z Fold 4, jump into Expert RAW settings and enable the Special photo options. Then, go back to Expert RAW's viewfinder, and you should see the mode in the toolbar at the top. Grab the latest Expert RAW update from the Galaxy Store.