What is the coordinate origin for FITS orientation in PRISM? TOP-DOWN or BOTTOM-UP

[dan_adrian]

Hello,
Does anybody know coordinate origin TOP-DOWN or BOTTOM-UP?

Thank you very much

[D SAINTE-CATHERINE]

In my experience, Prism is Bottom-Up and PixInsight is Top-Down by example.
That means you have to apply a Y miror on your images.

[dan_adrian]

Thank you very much