The Legendary Zuiko 18m f/3.5 Superwide Lens - Pop Quiz Question!

Hi all,

there may be an answer to this or then again maybe not...I've had a couple of these 18mm lenses in the past, I found it to be a very good lens and one I enjoyed using very much, so much so that I still have one in my lens drawer, however when reading through some literature I noticed that the original version has a fixed filter ring around the top as opposed to the more common 49>72mm adapter ring setup.

I would love to know from anybody if they have actually seen a version of the 18mm lens like this with the fixed filter ring

Also note that the newer version or the one I and other are more familiar with suggests that it is currently in development, although the original version with the fixed filter ring does not mentioned being under development which assumes this was in circulation before releasing the updated one?

Original version, text taken from The World of OM-Systems - Franz Pangerl and early OM System Manual for Zuiko Interchangeable Lenses Group

The newer version of the version - Text from 2nd Edition The World of OM-Systems Franz Pangerl and newer version of OM System Manual for Zuiko interchangeable lenses group

Thanks

Well I also just found this on

The Zuiko Lenses That Never Made It

Then there is the 'L. Zuiko Auto-W 18mm/F3.5' prototype with 12 element in 10 groups, and a fixed 72mm thread. This version was never marketed. The final version is multicoated (Zuiko MC 18mm/F3.5), has 11 elements in 9

So it seems it was never marketed, how interesting! I wonder why they dropped the front design?