Scaling the stack

[diant]

Some rose dreams...

Robin, good day!
How a great feature it may be, if Livestack would have a small box "scale stack" (may be from 50 to 200%)! We often meet a situation when there is some undersampling or oversampling. I often have an undersampling (when seeing is very good) and must rescale up my stacks during a post processing. But how a good improvement it may be if every subimage was stacking already in proper scale. I'm not even talking about real drizzling (HST-like upscaling) on the fly... dreams, dreams...
Anton

[admin]

Hi Anton,

interesting ideas - I think that the scaling at less than 50% could be either handled by binning at the camera level or by reducing the size of the saved final image without losing quality. On the other hand, scaling up would in theory allow better alignment by a small margin (although that would only really be useful if the camera was undersampling.

Have you used these sort of techniques in other processing software with success (or seen any discussions of using them for deep sky?) My understanding was that this sort of thing was more used in planetary imaging.

cheers,

Robin

[diant]

Robin, I can't tell you something about such discussions, but I really often use upscaling 140-150% when, gathering enough DSO (non-planetary!) livestack sums, combine them together in post processing. I used to upscale my sums in Siril (a sort of bad upscaling) or in FitsWork4 (dSinc method, for example; very good upscaling) and get a good result because I have some undersampling (f=700mm asi533mm 3,76mu pixel) and have in good (seeing) night a faint stars totally fall in some 2x2 pixels. Here is my example - M27 with upscale 150% (10h total light gathering on Askar 103 apo in L-enh and R,G,B, filters under 9+ Bortle). I would certainly prefer if my stacks were already 150% during stacking process itself (drizzling will be out of my most boldest dreams...).
Anton

[admin]

Thanks for explaining - I will keep the idea in mind, but I think it would be quite complex to implement, so I will not promise anything.

Robin

[diant]

Robin, I start this thread with the words "some rose dreams" with all comprehending, of course, how hard may be its implementation. So it's all right.
Anton