Focusing a 10-18mm f/4.5-5.6 is difficult ? Well, what do you expect regarding the DoF. :-)
That's not limited to focus-by-wire though.
The only way to do it is magnified live-view (which is what I am also using for all manual focus SLR lenses).
Honestly I would never use a DSLR viewfinder (without split-image screen) for manual focusing - it is completely pointless IMHO. All comments about manual focus accuracy are based on this use case (magnified live-view or magnified electronic viewfinder).
That's not limited to focus-by-wire though.
The only way to do it is magnified live-view (which is what I am also using for all manual focus SLR lenses).
Honestly I would never use a DSLR viewfinder (without split-image screen) for manual focusing - it is completely pointless IMHO. All comments about manual focus accuracy are based on this use case (magnified live-view or magnified electronic viewfinder).