krormark

<p>I used to have UV filters in front of my lenses as well but I removed them many years ago. I have not damaged any of my lenses till now. Regarding your photo to me it looks sharp. I am not sure how you took this image but your should avoid stacking filters on top of each other. If using a UV filter this should be removed before attaching the polarizer. With two filters stacked there is an increased of lens flare. In your image you have used a wide angle lens. You can see a slight tendency to the unevenly colored sky, caused by the wide focal length. The sky is darker blue to the right compared to the center and left parts. It is not so much in this case it is a problem. More important is the sun is more or less in front of the lens. For a polarizer to have effect the sun must be 90 degree angle to the lens.</p>

<p>I have never had any concerns with diffraction. This is not as important as someone will claim it is. Mostly it is "theoretically" as few of us will ever notice the diffraction unless told about it. The way we present most of the photos me make - online - it is not a problem at all. Only if you plan to make large prints it might be visible. If I need to use the smallest aperture at f22 for sufficient Depth of Filed I will use it.<br> At the end it is the composition and the execution of the image that counts. If diffraction is what is recognized by the viewer I would claim the image is not a good image. More important is to get rid of UV filters in front of the lens. Often people by cheap filters and put in front of their (expensive) lenses. This filter might sometime degrade the quality of the image more than the diffraction does. The intention of the filter is to protect the lens. Using a lens hood is often a better way to protect your lens from scratches.</p>