Hi Anders,

Good question, I think stretching will remove data as the preferred way in APP is always to use the linear data. I asked Mabula for a double check on that. I'd say that if you can process linear in another package, I'd probably do that. But I'll see what Mabula has to say as well.

I’m still learning Affinity, but thus far I have gotten much better results when importing stretched tiff versus linear tiff.

I would be interested to hear your experience with linear files.

Yes, so you indeed do limit your data with stretching. However, it is a good starting point, usually, for touch-ups in another package as the stretching APP does may be somewhat better. But, if the other package is able to stretch, you can always compare both and try to make them produce the same result. If that works, I'd likely do that and then save the result in the other package to a stretched one.

Thanks Vincent and Jeff for your input.

After some further tests and comparisons, I tend to agree with you. Loading a linear fits-file and stretching it in Affinity,  I have found it difficult to even come close to the result I’m able to achieve quite easily in APP. 

So revising my thinking, it may be a good idea to make the most of APP stretching facilities that applies to the whole image before exporting to a tiff format. Importing it into Affinity is still very useful to be able to take advantage of powerful generic image processing features like layering and masking for further enhancements.

I do not use APP for any post processing. I create the stacks in APP and then combine and process the .FIT files in another piece of software.