I'd have to agree with depscribe.
I got the Fuji LH-X10 filter adaptor/lens hood combo, and a Hoya digital clear in 52mm (surely the most difficult to clean filter ever promulgated by Western man). Besides getting dust behind it and on the lens, it could be difficult to unscrew apart to clean the filter. Sheeesh . . . . As above, I got the Marumi digital clear in 40mm (and 2Filter is great to deal with) and run the lens hood 'empty', and it's MUCH better in that fashion. And the lens cap slips right over the seated 40mm no problem.
Interestingly, Fuji seem to have taken the hint: Forthcoming is the LHF-X20: Fuji's own EBC clear in 40mm, with male threads on the outside, onto which screws a derivation of the previous lens hood, complete with a 'squeeze-in' lenscap that goes into the assembly. No word when . . . . or how much.
I'd also like to play with infrared, but I wonder if a 52mm into the adapter/hood would let visible light in behind the IR filter because of the air gap? Oh well . . . .