1. Install DSS by downloading the installer appropriate for your OS from this page: https://github.com/deepskystacker/DSS/releases/tag/6.1.0 (“Assets” at the bottom of the page)
2. Download some raw data from here:
3. Open DSS app ( not that not the Live app).
4. Click on Open picture files … on the top left corner of the sidebar. Select the downloaded FITS photos. These are your light frames.
5. Click on dark, flat, and offset/bias consecutively to add the dark, flat, and bias frames. These are your calibration files.
6. Make sure that all the images in all the tabs are selected in the bottom box. If not, click the Check all button in the second box on the left sidebar.
7. Click on Register checked pictures…

test