I have 3 lenses that I am trying to find filter rings for. I've been unable to after searching for a while so I hope you all can help.

1. Goerz Red Dot Artar 14" f9 - appears to be a course thread. It looks to be somewhere around 52mm.

2. Goerz Red Dot Artar 9 1/2" f9 - fine thread. It looks to be somewheee around 40mm.

3. Wollensak Velostigmat Series II 7 1/4 f4.5 - fine grain.

Thanks for your help.

I wonder if this is the kind of thing we need a sticky for.