It's well known that Leica wide angle lenses on micro 4/3 produce extreme smearing on the edges.
Even Leica digi's have software to correct distortions. That's why the lenses have to be machined with 'codes' for the digi computer to read and apply the corrections.
That's why digi's need firmware upgrades and the lenses need firmware upgrades too. To adjust the corrections. Non computerized lenses do not have firmware. Therefore, no corrections.
Because digi buckets can not capture light from an angle, their lenses are designed to straighten the light path to the capture device. This introduces bizarre distortions which, again, are corrected in software.
Smears or distortions. Choose your poison.
Chromic Aberrations are another problem.
Thank God film is still on this planet. No firmware required.