I re-ran the tests of the previous post with the WATE set to 21 mm focal length.
The Expodisc images:
f/4
f/11
f/16
The corners are fine.
The garden scene:
The upper right corners:
More than a bit soft, but not as soft as at 16 mm.
OK
The best all around f-stop
Softening a bit.
Still OK
Pretty blurry.
I’d say this lens is just fine on the a7S.
Any thoughts on the diagonal cross-hatch pattern and weird artefact that appears toward the top of the left edge in the Expodisc shots, particularly visible at f/8 and above?
Good eyes you have! It’s light leaking in through the little cutout in the Leica lens hood. The cutout is Leica’s workaround since the hood blocks your view when you’re looking through the finder in the camera.
Never mind that the finder in the camera doesn’t have a setting remotely appropriate for any of the WATE focal lengths. For that, Leica will be happy to sell you the Frankenfinder, now thankfully obsolete in the M240 thanks to live view.
I know what you’re thinking. None of that makes any sense.
Jim