Asymmetry with Leica 180mm f/3.5 APO-Elmar-S
Related: apochromatic, focus skew, Leica Elmarit and Elmar, Leica Lenses, Leica M, Leica medium format, Leica S 180mm f/3.5 APO-Tele-Elmar-S, Leica S Typ 006, lens mount / sensor parallelism, lens skew, medium format, optics, quality control
The full discussion of this asymmetry is found in my review of the Leica S2 in DAP.
Brand-new, the Leica 180mm f/3.5 APO-Elmar-S showed a soft right edge, with a very crisp results elsewhere. Multiple field shots confirmed the issues. For a US$6500 lens, this is very disappointing, to say the least.
Though camera alignment cannot be ruled out, I observed no issues with the Leica 70mm f/2.5 Summarit-S ASPH on the same camera body.
Shown below are actual pixels crops from the left and right edges respectively. Not shown, a foreground area and other confirmation shots confirmed the issue without a doubt.
Stopping down to f/5.6 can (mostly) overcome the problem but it should never be considered an appropriate “solution”.