I have never used filters on my lenses unless they were specialty filters (star, soft focus, etc.) in the film days. I know that most digital images benefit from 'haze' sharpening. Anybody have any preferences on using filters on lenses and why or why not. I know we all say I would rather ruin a filter than a lens but I never had a problem with that. The coating on the lenses has gotta be better than it was 30 years ago. So, let's put opinions out there.

The only filter I use is POL filter, when not using that, my lenses are naked.   

I agree w/ hotrod.  I use a Circular Polorizer, and that's it, the only other one that I can see being advantageous is a grad ND, but that is only useful if you can't photomerge, or there are moving objects in the frame.

The only time I will put any kind of protection filter on my lens is when I'm in harsh conditions, blowing sand, hiking through thick woods or something like that.  Most of the time the lens hood does a pretty good job of protecting the lens. 

Generally unless you get really good quality filters there is some image degradation, sometimes not much with good filters, but you're still shooting through another piece of glass that affects your final image.

 I only use B+W multi-coated (prevents/reduces ghosting/reflection from sensor on digital cameras).  The only exception to that is that I have a Hoya RM72 infrared filter.  All that said, I also only use them in harsh conditions or to accomplish a particular shooting need (C-Pol, ND filters to attenuate light for long exposures, etc.).

Jim