Can anyone suggest an effective way to cleaning filters for the Z1, especially the polarizer? Someone suggested using warm soapy water but I haven't tried this.
I find that the polarizer is very difficult to clean, using recommended cloths or spectacle spray, whatever, it just seems to make it worse and I end up with smears all over the glass.

Further to my message, I've tried using a small drop of Windex on a microfibre cloth and that seems to work fine.
Thought I'd answer my own question in case anyone else runs into the same problem.