Good Morning All, Thank you for your kind postings. I have attached a couple of photos that have been cut to show the dark corner. With that said, I'm not using any filter nor a hood, it's a most perplexing. At first I thought it might be vignetting, now I'm not sure because it's only the one corner and it changes size with distance. In some cases it almost disappears. Just for my own scientific process I snapped a photo of a whiteboard, here the issue can be clearly seen. Any help would be greatly appriciated. Thank you