I need a 67mm polarized filter. What is a good brand? I have a Nikon D7100.
If you are talking about a circular polarizer I bought a cheap Sunpak a while back and ended up buying a Hoya later on. The Sunpak works but not smoothly.
Stick with Hoya, Tiffen, or B+W and buy from a reputable dealer like B&H or Cameta.
Make sure a lens cap will fit on the front. There are some "thin" filters that a cap will not clip onto, unless you never use a cap the never mind. Those brands above work well, I like Hoya for value and quality.