Hi Anh
As I explained I can't post a RAW file but here are 100% crops from the four corners .
I only took a few test shots to see how well the corrector works ( its similar to the TSRED379 , I really bought the scope for visual but have now stepped up to a 6" refractor.
The pic is taken with a full frame Nikon Z6 focused without mask so maybe not perfect focus , can't remember what the seeing was like.