blonde wrote in post #2992835
see, now that makes perfect sense and should have been in your first post

anyway, i have not used them but i did use a few Hoya's. altough the Hoya is great, i think that i will not buy them anymore because cleaning them is quite a pain. i am sure that Nikon knows how to make glass so i am sure that your NC will do quite nicely. i also know that Sigma makes a few filters and they are great where in contrast, the canon filter that i bought when i started out was a joke.
I had a thread about Sigma's, they are supose to be bad.
I'm going for Hoya's for all my other lenses that aren't high priority / going to be used as much as the 135L.
I'm curious why they are hard to clean, I've heard this before. My friend cleans his NC / lenses with eclipse optical fluid and pec pads, and it works beautifully, that stuff dries instantly, I would think it's fine for Hoya's too?