Recommendations for filters...

Using filters for protection is a contentious subject for many photographers.  As you know any additional glass in front of the lens can lead to degradation of the image quality.  Some people will put protection above quality and others quality over protection.

I normally do not use filters on any lens except for special effects (polariser) or in adverse conditions (protection) and in over 50 years of photography have never had any damage to any lens element.

As a Canon user, I only use their protection filters on those occasions where protection of the front element may be necessary eg. sand and salt spray at the beach.

http://www.pbase.com/johngwill/image/35929325.jpg

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John W
Advice is what we ask for when we already know the answer, but wish we didn't - Erica Jong: