I think this will work
no, that one will not work. here is what
work, because it is threaded all the way through, 49mm, on the inside:
now. for those who inexplicably purchased the X100 in the erroneous belief that it is the best choice for macrophotography, there needs to be added also this:
after which you add a 52mm UV filter and this:
and then you can macro to your heart's content, all for less than $20 plus the cost of the filter which can be from $5 to $50.
some pictures: http://www.flickr.com/photos/depscribe/collections/