B+W Kasemann filters?

[matthew_h]

Can anyone explain what the "Kasemann" bit means on some of B+W's CP filters?

I'm looking at getting a new 77mm CP to replace my cheapy one and can't seem to establish what the kasemann bit means and whether I need it or not.

Can anyone help?

[jason-l]

They are edge sealed which means water/dust/cleaning fluid can't get at the foils between the 2 layers of glass. I believe the filters are also re-polished after assembly and before mounting.

A lot of the larger dia. Kasemann filters aren't coated, which may/may not be a concern. Arguably you don't need coating on a polariser since the sun would rarely be in shot... but highlights still could be!

Be aware that B+W made a batch with dodgy lubricating grease - which is impossible to clean off the optics. Mine had this, and a 2 week trip to Germany got a replacement with a different grease.

[matthew_h]

Aha, cheers for the info. Sounds like a development that I don't really need and can probably live without.

I shall look into things further.

Thank you