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:
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
I don’t see any grains on focus scales. The paint is quite smooth.
I will leave the numbers to those with proper protractors.
Your best bet, if you are interested in measuring FC, is to check out the measurements that Roger Circala sometimes makes and generates as a chart showing the area of sharp focus.
It's not just geekery, but cab be quite useful. For example, the ZF/E classic 1.4/50 has a reputation (from MTF measured with focus at centre) for being very unsharp over most of the field wide open and only sharpening up as you stop down. But his zone of sharp focus chart (he has some other name for it, sorry) shows that this is mainly just FC, and if you focus off centre you can get perfectly sharp results (albeit it won't then be sharp at the centre.
For the usual uses of f1.4 lenses at wide apertures this is fine; you usually have a determinate subject which can be sharp, and the rest of the field doesn't matter much. The only downside is that if the FC curves back rather than forward, it can make backgrounds less smooth in the periphery.
That's the only way I think that the FE plus version is likely to be an improvement on the the M version of this new lens. I think for stopped down use the corners of both are likely not that dissimilar. But maybe (only time and testing will tell) if you have a centralish subject that is quite close at f1.4, the backwards field curvature may make the corners less blurred in the M version when used on a Sony sensor.
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/
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:
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.
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.
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.
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 wide 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!
David, do something about the auto correc/typo. Uncorrected wife? No OLAF in this universe can discern that!
DavidBM wrote:
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!
The B&H link is to the M-mount version. I wonder if they’ll also stock the FE Plus version? In any case, this thread—mainly thanks to Vivek’s advocacy (supported by images!)—has piqued my interest in the 7Artisans 28/1.4 as a possible complement to my Biogon 28/2.8 ZM. I like the idea of buying (the M lens) from B&H because of their generous return policy but is there any advantage to getting it from 7Artisans?
Okay received my lens from China tonight. I did shoot some test shots and looks very promising for even landscape at F8 extreme corners maybe of a touch off but its really nice. I dont want to post the interior shots yet. Like to get Big Bronco but that's 2 days of rain away. But i did take a shot of the lens with a couple buddies with it. Built very nice and you know you have a lens in your hand.
I do think we may have under estimated it a little at least i did on center it needs like F2 or even 2.8 but lets wait till center tests
This is NOT a test. Well it is but I'm in the rain shooting but I certainly will go back out in full sun as I normally do. This does look promising and better than what i expected.
I do not have a Lens profile obviously and it needs one or maybe we can find something similar . Well I tried the Laowa 15mm in the second image
So First image not distortion correction
Second Image I used in PS the Laowa 15mm and it does look better
It actually fixed the handlebar a little. Obviously we need a profile or find something that can do a good job on it.
As you can see the image is extremely Flat in light so i do not want to judge color or anything like that for now. But I did focus on center than stopped down for my first series like i always do and than on the second series I focused on the corners and went from there. I see no discernible difference in post.
But don't take that as gospel either im focusing under the worst light possible. So that needs to be done in full sun. Not that I messed up im sure I did not but like to be safe on my facts. You all know how I hate bad info. Let me add here since I just said that. This lens was purchased because i was interested in it, if it sucks it goes back if its good I may keep it. I dont have to justify it to myself for even a split second. So whatever is posted is HARD COLD FACT. Im a little tired of people justifying junk. But that's another story and I really dont care if I keep this or not. I would like to see it work out though. Sometimes that just needs to be said. This is just a recording of data
