Nicloks

Thanks so much for the detailed responses. @Lisbon I used your method with really amazing results. I added a bit of feathering and exposure alterations and the black holes left by the Defringe process are all but gone. Only issue is that during further processing there is a slight haloing outside of the Defringe artifact area which become apparent. I'm sure I'll mitigate that with some effort though. This is true, however economic realities also have to be dealt with. I shoot on older Sony FF cameras and this image was shot with the Samyang 35mm f/1.8 (@f/2.2) Tiny Prime which is $500 where I live. The Sony 35mm f/1.4 GM is probably the best/brightest performing 35mm for astrophotography of any system, but costs $2000. I certainly wouldn't be dealing with CA or other aberrations to nearly this level, however I also wouldn't be eating as there is no way I can afford it.

Thanks for the replies. I'll check out that PixInsight link for sure. I've attached a 300% crop of a problem area, first photo prior to any corrections, second with CA and Defringe and finally with the colour selection and HSL layer to desaturate and bump luminance.

Hi All, Not uniquely an AP problem, but I find I have significant issues removing purple fringing from my photography. I usually stack outside of AP and export the stack as a 16-bit tiff which I then edit in AP. I find the CA filter does very little and while the Defringe filter does the job, it leaves these dark halo's which I find next to impossible to fix. I've had better success removing purple fringing by doing a color select -> grow -> feather to a mask on a duplicate layer and then using HSL to tweak saturation and luminosity. This still leaves the stars looking bloated which are then troublesome if I am looking to do star reduction work. Aside from getting better glass for cleaner acquisition, what can I do inside of AP to remove purple fringing without leaving terrible looking artifacts behind?

When creating a new stack the layer order is pulled into Affinity Photo in descending alphanumeric order based on filename. There is currently no way in Affinity Photo to alter this order by layer selection en masse which creates a significant hindrance to workflow where many dozens of layers are in use. Would like similar functionality to PhotoShop where the user can select the layers needing a different sort order, then selecting the "Layer" menu, "arrange" menu item and then "Reverse Order". Assuming something like this would be best suited under the "Arrange" menu and would allow the user to sort their selected layers in ascending or descending order.