So, I've recently purchased a Panasonic Leica 15mm f1.7 for landscape astro. There is some noticeable C.A. appearing as purple halos around large stars. https://i.redd.it/fc0wv33wevo01.jpg Image shown is 100% crop, about half way from center to edge. Image data: Oly E-M10 II, PL 1.7/15mm @ f1.7, 15s, ISO 1600 Can anyone provide advice on the most likely reason for the severe C.A.? 1) That is a normal amount of C.A. for a lens wide open 2) The PL 15mm corrects C.A. badly 3) The PL 15mm has bad C.A. when used on Olympus bodies 4) Image is a mis-focus 5) I have a faulty lens copy 6) Something else?