Create your best image of Saturn

Great pictures of the ringed planet start as video, before stacking and processing

- Martin Lewis

The best way to produce your own full-colour image of Saturn is to first capture a correctly focused and exposed video of the planet, a minute or so long, using an astronomical digital camera at the focus of your driven telescope. Here I'll explain how you then process this video to create a single final image of the planet; I'll assume you are using a colour digital video camera as this is the easiest way for you to produce a full-colour image.

At the processing stage, you use special software to break your video down into separate frames, rate each frame for quality, then align the best ones so that they all lie exactly on top of one another. This results in a single-frame stack. This stack is effectively a long-exposure image made up of lots of carefully aligned single, short exposures. The long exposure averages out the chaotic movement in our atmosphere and also means the noise is much reduced compared to the much shorter-exposed individual frames. This allows stretching and local contrast enhancement methods to be applied that would be pointless for the much noisier single frames.