[jet_kit]

I agree with Steve. Kood & Hoya are amongst the best on the market, your camera's 'own brand' will probably not be any better.

But in today's quest for ever more definition you have to look at a filter as the addition of two more glass/air surfaces in the lens array. Unless it's giving you an effect that you are unable to achieve in PP, then use for protection only when in hazardous situations.