[JJ_SO]

At this stage it's worth mentioning that users may be loyal to companies but companies are never loyal to users.

 

See Samsung (NX- & NX-mini), Nikon 1, Four-Thirds, (plus historically Oympus OM, Canon FD, Minolta MD, Leica R, etc).

 

Next in line: Canon EF-M, Pentax Q, Sony A, Leica T

 

And outside of photography but part of the contemporary workflow: Apple who were always very "independent" on how much users invest in their "latest technology", be it FireWire, CinemaDisplays, certain hardware for iPodPadPhone - incredible how much user money this company dumped in the bin. Okay, there's always a risk for the one first coming out with a new "standard" and no user is forced to invest in "latest tech".

 

dave, with calipers you can't measure down to 0.01 mm reliably. I should take the converter which is neither worn out or malfunctioning to the grinding-lab where they can measure down to 0.1 µm and find out how parallel it really is. Again, even given the outmost perfect manufacturing, an adapter is always only second best. If you enjoy  little read about that:

 

https://www.lensrentals.com/blog/2013/09...-adapters/