this guy have a filter hack for it. 77mm filter + step up ring and just slide it into the hood.
check around 3:26 into the video
you dont need the stepup ring, that's why he can only go down to 16. Tape is all you really need, gaffers preferable. With the right amount of tape, you can get down to 14-15. If I put on the filter really carefully and check the 4 corners, I can get down to 14, no vignette. Sloppily putting on the filter, then around 14.5-15. 16mm is if you have a stepup ring, which you dont need, best to fiddle with tape, it doesnt take much effort to get it right I dont think. Took me like 5 minutes.









