You might want to consider a Mamyia 6 from the 50s, not the modern 6. It is a folder, 75mm coated lens, I can use S VI slip on filters and hoods. The range finder is somewhat small and dim by modern standards but useable, and you need to cock the shutter, other wise a very compact 6X6 camera. What is somewhat unsual is that the camera focus by moving the film not the lens.