I will be ordering a breakthrough filters one next month for the same lens, a mate uses their stuff and I was impressed with his results. It will be next month as I have their X100 system and 3 and 10 stop ND filters on order. The 25yr guarantee they offer was also impressive. It was about 115 quid, my only experience of filters previously was a cheapie off ebay and a hoya pro on my 58mm lens