I have a 200mm Newt and live about 5km from the CBD of Melbourne so I'm looking for any edge to reduce light pollution. In a nutshell do these filters enhance contrast on planets and cut down artificial light pollution? I like to see the natural colours on planets and rarely go for filters on them but I sure am interested in cutting out artificial light and darkening the backdrop behind bright objects I am viewing through my eps. Most of the reviews are okay but I noticed a lot of the reviewers are using refractors. I'm looking at the 2" variety for the Newt.
The Baader Moon & Skyglow (Neodymium) filter has a very mild effect. It won't hurt to have one in your armoury - in superb observing conditions I've experienced minor but useful enhancement of Jupiter's cloud bands - but don't expect major gains in the light pollution reduction/contrast enhancement areas that you mention. The various UHC filters do far more, particularly for suitable nebulas, but will cost you significant brightness on non-nebular objects of interest. Some of these filters will also introduce distracting star colour artefacts.
Like you, I observe from a heavily light-polluted suburban area and in my experience (exclusively with SCTs, not refractors or newts), there isn't any 'magic bullet' for light pollution reduction/contrast enhancement, despite the claims of filter manufacturers. I'd recommend you try examples at a star party if possible, failing which, buy second-hand examples rather than paying full retail for filters which may disappoint you.
John have a read of this thread from cloudy nights on OIII filters which may be more along the lines of what you are after. I too have lots of LP and thats partly why I prefer refractors over reflectors.
Matt
