Stacking the data

In astro photography you don't process the photos but the data. They are essentially the same just differently referred to. I am not going to write a whole manual. Not possible. What I will do is point out a few things to manage expectations a bit. Writing is an ongoing process and insights will grow and shift so this will be quite a dynamic page.

Amongst quite a few application I like to use Astro Pixel Processor. It is a payed application that is very good at stacking the data. It is loaded with parameters of which possibly only Mabula Haverkamp (designer and programmer) knows what they all are for.

Stacking can also be done in the ASIair but that is a very rudimentary algorithm that only adds the data but that clearly doesn't do a good job in removing noise in the brighter parts and it doesn't remove satellite trails as you can see in this stack of 47 exposures of 180 seconds with darks, flats and biases:

The next photo is exactly the same stack only stacking now took place in Astro Pixel Processor (left) and processed in other software for the end result:


The last one is the same stack but has been processed within Astro Pixel Processor in a different way: