Mark -- All Nikon 77mm filters obviously work fine, as will thin profile filters from other manufacturers. I have also modified a Cokin P holder by sawing off the front two slots, and then cutting off the outer portions of the rear slot except for the part that contains the spring, essentially leaving only about 3/4 an inch of the slot in the center of the holder. This allows use of Cokin P rectangular filters (for me, the Singh-Ray models) with no vignetting at all focal lengths. I also put a Signh-Ray polarizer in this holder, but it will vignette below 24mm. Just be careful with Cokin 77mm adapter rings, they bend easily. Good Luck Matt Cox Parker, CO ---------------------------------------------------------------------------- "I would be interested to know what filters the owners of the 20-35 2.8D are using successfully without vigenetting. I looking for info on what brands, models, etc. you, the owners, are using on this fabulous lens? Thanks again."