Fuss-free tools to process your DSLR astro images

Using freeware to stack, extract the background, calibrate colour and more

- Charlotte Daniels

Astrophotography can be an expensive hobby and one where we constantly seek perfection from our data. While processing is a crucial step to achieving image excellence, many processing software packages come with the cost of monthly subscriptions. But that's not the case with astrophotography freeware Siril (siril.org/download).

Siril performs many functions including image stacking and auto stretching, and it interfaces with external programs such as StarNet++ to remove stars too. This lessens the need to jump between various programs and simplifies the workflow for beginners. We won't focus on these functions, however, and will instead run though a few key features of Siril's 'Image processing' suite. The latest version of Siril, 1.2.0, was released in March 2023 and is available across Linux, Windows and macOS platforms. For this article, we installed the Windows 64-bit version.

A bit of a stretch