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Drizzle and binning

Posted: Wed Feb 17, 2021 9:46 pm
by NGC664
Still learning Star tools but since I am using a Sony A6500 with 24MP capacity I have been binning to 25% with good results. My small stars under magnification are about 3 x3 pixels. If I 2x drizzle in DSS ,how does that factor in when it is time to bin my FTS file. Really don't understand if there is any correlation with file size. Anybody can help? Thank you

Re: Drizzle and binning

Posted: Thu Feb 18, 2021 5:55 am
by admin
Hi,

You should never be drizzling unless your data is undersampled. Drizzling is a last-resort measure to counter undersampling. It requires very good, sub-pixel sampling of the night skies. In your case, at best stacking will take much longer, at worst you will end up with a poorer dataset.

To answer your question specifically, using 2x2 drizzling will make your datasets 4 times as big (2x multiplication in the X and Y axis). Given you say you need to bin to 25% anyway, drizzling would do nothing for you (your datasets are oversampled not undersampled). You would have to bin to 12.5% with a 2x2 drizzled dataset instead.

Hope this helps!