Quote Originally Posted by Ian Grant View Post
It's an odd filter size, I use a 40.5 to 49mm stepping ring

For LF work that's what I do, except it's 52mm. But these are for a couple of lenses for my new-to-me Zeiss Ikon ZM rangefinder. I haven't experimented yet, but I think a big stepup like that would partially block the viewfinder. And then there's the lenshood issue...