GX680 65mm wide angle - missing part?

[Simon Benton]

I have obtained a 65mm f5.6 Wide Angle lens for my GX680 and I think a part must be missing from the front - maybe the threaded ring that holds filters? Can anyone confirm this and does the part have a technical name. Or is there a lens hood that screws in here?

 

[pbryld]

All other lenses have the ring that holds filters (and caps) so I'd say that is definitely missing.

 

[Simon Benton]

Mystery solved. In the filter thread part was screwed this additional ring with its own external thread. It was screwed in very tightly but I managed to remove it - I have no idea what its purpose was. Thanks for all the suggestions.

 

[Aja B]

The adapter piece you removed is referred to as a step-down ring. It permits mounting a filter with a smaller ring size (e.g. 77mm) onto a lens whose filter ring is larger (e.g 95mm). The ring-size steps down from lens to filter. (Notice the potential for vignetting.) A similar adapter, and the preferred scenario, is to use a step-up ring (smaller lens ring-size to larger filter ring).