Note the characteristic waveform (or 'moustache/gullwing') distortion
of the Zeiss, verses the moderate barrel distortion of the Leica.
This really is very good for a prime, let alone a zoom, but the trademark
reduced contrast/high resolution Leica look just isn't working here:
pictures are uniformly softened across the frame at this focal length.
For comparison: the Sigma 20mm f1.8 at f11 (100% corner crop below).
This pic flattered by better light and different colour temperature
on a different day, unfortunately . . . however, from experience,
this is representational: it resolves at least as much as the Leica
in the corners, are more in the centre of the frame. Note the Zeiss-like
accutance, resolution and monster waveform distortion.
For comparison again (below): the Sigma 15-30mm at f11 (100% corner crop).
Not a bad showing for such a cheap lens - it's better in the corners and no
less sharp in the centre at f16. Which doesn't excuse the yellow cast....
The Man in the Shop said that the Leica 21-35 would do unspeakably
scatological things all over the Zeiss 21mm - which I though incredible.
Sure enough, the Man in the Shop was wrong.
The Leica may be the world's best
wide angle zoom (if only we could test the Contax N!)but at 21mm it isn't
the same lens as it is at 28mm. The Man on the Leica Web Site, however (who
investigates these things rather more fastidiously than the Man in the Shop),
has also noted the performance drop-off at the wide end of this lens, from
which I drew a small measure of comfort that largely failed to assuage the
financial pain of selling the lens on after a single shoot.
At 35mm, it is as good as the Zeiss 35mm Distagon, but at 21mm, it is outperformed
by either Olympus 21mm, Nikon AFS 17-35mm, and for resolution (if not distortion) is
even humbled by the Sigma 20mm f1.8 EX.