My current project camera came with a Hugo Meyer RF that, after cleaning 60 years of grime, spiders, egg cases, ect out works very well, with a strong double image. My question is this: the Meyer RF was made in different sizes to accomadate various focal length lenses. How were the different size Rfs marked? The camera in question came with a 15cm lens, and the RF was marked '5'. Is there a scale of RF to focal length in the collective database?
Thanks, Top