Reviewed: Kolarivision-Modified Sony A7R II with Leica 18mm f/3.8 Super-Elmar-M ASPH
Get Sony A7R II mirrorless and Leica 28mm f/1.4 Summilux-M ASPH B&H Photo.
Ray angle of rangefinder lenses interacting with the relatively thick sensor cover glass of the Sony mirrorless cameras introduces severe astigmatism in outer zones, along with lateral chromatic aberration.
Astigmatism can be understood as “two planes of focus generating a double image”. These are the sagittal and tangential foci, as used in MTF charts.
Completing my three M-lens survey, a specially modified Sony A7R II (KolariVision) and a stock unmodified A7R II were used to explore the performance of the Leica 18mm f/3.8 Super-Elmar-M ASPH.
Along with the similar Leica 28/1.4 Summilux-M ASPH analysis, this analysis of the Leica 18/3.8 further substantiates the severe quality losses with Leica M and Zeiss ZM wide angle lenses on Sony Mirrorless (without the Kolarivision mod).
Sony A7R II Kolarivision Mod: Leica 18mm f/3.8 Super-Elmar-M ASPH
See also my analysis of the performance of Zeiss ZF.2 lenses on Sony Mirrorless in Guide to Zeiss (full aperture series as full lens evaluations for several of the ZF.2 wide angle lenses).