B and W polarizer defect?
I have three B and W Kaesman slim circular polarizer filters (MRC). All were purchased about seven years ago from an authorized dealer and I doubt they are counterfeit. I was cleaning them the other day and noticed that the front surfaces are not perfectly smooth. When viewed under a tangential light source I can see what appears to be very fine crazing of the surface similar to laquer cracks on old furniture. These are extremely tiny and one has to look very closely under just the right light to see it. It is mostly on the front surface and and varies in degree between the three filters. On one it is very noticeable and on one it is barely visible.
Has anyone else noted this on B and W circular polarizers? More importantly can anyone give me advise on how to test the filters for any degradation of IQ? Three of these filters is unfortunately not a small investment. Thanks.