Just something of interest I found when browsing dpreview's forums.
This guy bought some cheapo UV filter which came with his 24-85mm lens and got bad image quality with it, so he (incorrectly) guessed the glass was lousy and thus sold it off. But he discovered the images were soft with his 70-200 f4 too with the same filter mounted. So he did some tests with and without filter on and the results kinda speak for themselves. (See this too: http://forums.dpreview.com/forums/re...essage=6219216)
So it is true that the type and brand of filters that we buy and mount on the front of our lenses do affect image quality to a certain degree. (specifically UV filters since they are the most commonly used and are supposed to have a "neutral" effect on the image). But by how much I wonder? Anyone can share his/her experiences with using different brands of UV filters and does it add great difference to the image quality? It would help if you could list which particular brands and models are the recommended ones too. Thanks in advance.