Originally posted by stevebrot Perhaps the filter is delaminating?
That was my first thought too.
De-lamination is common with polarisers, I have never seen it occur with my Lee Polariser or ND filters. Though with certain mid to low tier filters I have seen all kinds of manufacturing disasters.
This is isn't a simple matter of light entering the viewfinder which invariably leaves horizontal lines on the image, this could be a bizarre combination of things going wrong at the same time - I'm looking at the fogging and deep magenta cast that appears on the right side of the shoreline.
You weren't trying to use pixel shift by any chance?