"Black Glass" vignetting issue with the RX1
I recently purchased a B+W 10 stop ND filter as I live near water and wanted to experiment getting that hazy effect on the lake. Over the weekend I put the filter on my camera at home after removing the Neutral B+W I typically use for protection. It was well below freezing and forgot to consider that the lake may have frozen up (which it did) so knew when I got there I would not be getting "misty water".
I was there and it was cold so did not feel like changing filters again so thought I would experiment with timing with this filter on to see what it would take to get the right exposure under conditions. All seemed to work well but identified I get fairly significant vignetting. My Neutral filter with the same physical design by the same manufacturer does not give me vignetting.
Is this common with these 10 stop filters? Am I doing something wrong? I'm ok with this resulting image but do not think I want to see this look every time I use the filter. Why this issue with this filter and not the Neutral? Is it a defect?