I chose this first filter for its price and the Hoya brand. Then by using it, I found it really very powerful (not compared with B + W polarizing). Tried on a Canon 17/40 and tripod, dull landscapes reboostées and win in relief, and without visible loss of sharpness. Made of the loss of about two stops max, I could make long exposures covered in undergrowth from time to f / 16 or f / 22 with exposure time between 5 and 30 seconds. The rotating ring, thanks to toothed parts, easily mania. Screwing / unscrewing the filter, even if the thread is very thin, do not ask me big problems, and again notched small parts helps a lot.