Which light pollution filter for astrophotography?

[5ash]

I am taking pictures through A SW 120ED using an unmodified Canon 60D and would like to get a 2" filter to reduce light pollution and sky glow . Which filter would be best value for money with my setup.
Regards philip

[DigitalNightOwl]

The Astronomik filters are really good, but quite pricey too.

[ZeroID]

Astronomik CLS seems to get most peoples approval

[cometcatcher]

Depends how bad the LP is. You may need anything from a gentle wide band filter like the Baader Moon and skyglow to something like the Astronomik UHC.