Problems with distortion, reflection or other, typical "filter phenomena" I've never experienced before with the Hoya Pro1.
The filters can be screwed without problems on the lens and turn comfortably there by 360 ° in every possible position, so that a very individual desired image result is producible. In nature and landscape photographs of the filter is an "always on it" with me!
From me there for this filter unrestricted recommendation to buy, want to make more out of their images for all!