Alex I use classic cameras for all of my work, folders,tlr's etc, and it can bee very hard to get filters for all of them, so I have filters for some, and those that I cannot get the right size filters for I simply fit slightly oversize filters over the lens with blu tac, maybe it doesn't look that smart but it works, just make sure that you use a slightly over size filter to avoid vigniting, I also have a yellow cokin filter cut down to fit some lenses again with blu tac,Richard