realVivek wrote:
I am confident that won’t happen. I think you are overthinking the field distortion due to the cover glass thickness. Keep in mind that I do have a Leica MM and have used many adapted lenses on it and quite a few are non Leica. Besides, I have Sony cams with varying cover glass, including one with no cover glass.
DavidBM wrote: realVivek wrote:
Thanks!
I don’t see any grains on focus scales. The paint is quite smooth.
I will leave the numbers to those with proper protractors.
DavidBM wrote: realVivek wrote:
I would love to see field distortion measured and expressed in numbers to be objective. Rest is subjective.
FWIW, i was impressed with the Summilux 28/1.4 images (on a M camera). The 7A 28/1.4, when came out, i grabbed one. I am glad I did.
Quite an impressive lens, in general and an impressive accomplishment for 7A.
FWIW: on the street snap, no sharpening was applied at any point. The camera had an inexpensive replacement metal mount (makes a world of difference).
Easy way to do it
At infinity focus for centre, focus for corner, see the difference on focus ring (needs a very fine grained ring to get numbers though)
For say 3m: find a brick wall, set camera parallel, focus for centre. Measure exact distance to wall. Moce camera without changing focus ring until corners at optimal focus. The difference between the distance that the camera is to the wall and the old is the degree of filed offset between centre and corners at 3m
This raises an interesting question: what happens when you use the FE plus version (which recall, still has an M bayonet) on the M sensor? Possibly you will get *forwards* field curvature , which can have a really nice effect on the bokeh of a lens focussed on a central, close subject/
The point that genji raised in one of the posts above is quite valid. Some lenses, regardless of the sensor glass thickness just don’t do well in the corners. Leica themselves are constantly updating their lens line up to address the issues with the fuzzy corners.
That is NOT the case with the 7A design!
Jonathon is of course right, FC is by no means the only cause of poor corners. Indeed FC is not a cause of poor corners at all, except when you have a planar subject parallel to the sensor plane, or are at infinity, and are focussed centrally.
But that doesn’t mean that there isn’t induced FC with wide to normal M lenses on Sony in many cases - look at the huge thread on people getting small but meaningful improvements in FC with add on lenses.
Nor does it mean that an uncorrected wife to normal M lens is not good or even very good on Sony. Just that, often, correction brings small improvements in certain situations.
I look forward to seeing comparisons between the two variants of the 7A!
