Excerpt: I got this filter to protect a new super-telephoto lens just before travelling to Borneo. Given the jungle conditions and trekking style of our trip I wanted to make sure I got some extra protection for my new lens. It worked great and I was able to get some awesome photos. No problems with focus, etc. For the price it was a no-brainer and I'm very pleased with it.
Excerpt: This filter fits perfect and does the job and keeps the blues to a minimum when Im just inside the shade but shooting into bright sun. Great for non sky pics, and protects the big 86mm glass on my Sigma.
Pros: Compact, Easy to Use, Great Picture Quality, Lightweight
Summary: This filter resolved a major problem with my telephoto lens. I had purchased it second hand and it had come with a cheap off brand C PL filter which was causing auto-focusing difficulties. Once replaced with this filter the focusing cleared up.