Steve Spencer Offline Upload & Sell: On
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retrofocus wrote:
Good test, indeed - I just suggest to add some photos which might show the differences seen in the tables. I found this remark very interesting in reference to the tested Leica 24/1.4 ASPH lens: "The absolute corners, however, hadn't changed a great deal. Whether this is because the sensor-stack change isn't helping enough at extreme angles, or because of other factors (micro-lens alignment on the sensors for one, perhaps raw data manipulation in-camera, or stuff I haven't even thought of), I can't say."
So other factors seem to play a crucial role here, too. Again, photos taken with this lens on a regular A7R and on one with modified sensor stack might help here....Show more →
One very plausible, IMO, explanation for the midfield and not corner improvement on the 24 Lux ASPH is that if the lens has pretty poor corners wide open even on the Leica cameras, there may be a limit on how much reducing the sensor glass can improve performance if the lens just can't perform well in that zone. Especially if this reduced corner performance is due to curvature of field, then thicker cover glass might exacerbate the curvature and affect mid zone performance primarily, and reducing the thickness of the sensor glass would then increase mid zone primarily, but the normal curvature of field would still be affecting the corners.
One way to examine this that I would like to see (I hate asking Roger to do more, because it is great he does so much already) is how the lens does in the same set up on a Leica camera. If a lens has weak corners on a Leica M, we can't expect reducing the cover glass on the Sony cameras to somehow make sharp corners.
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