Alan Gales
Member
Fitting filters of any kind is a challenge when using old or cadged-together lenses. It's possible, but the size needed and the mounting difficulties have led me to work around the question by using very slow media, like paper negs.
Yeah, some old lenses have weird size threads. Sometimes you can get a step-up ring close enough to fit a little tight and just leave it on or you can tape a filter onto the lens. Like you say, it can be a hassle.