Thanks for the podium finish. Actually there was no post editing at all, other than shrinking the file size so that I could upload it here—other than that, this was the actual jpeg file output by my Panasonic GH5, and without using any of the built-in image effects either. I hadn't shot digital for so long, I totally forgot to check if I set the camera to save raw instead of jpeg. I may have had a physical polarizing filter on my lens, but if I did this would have been unintentional—I might have simply forgot I had it on.