mikedefieslife wrote:
Why on earth does that review look at corner sharpness at f/2? Especially on something that's not even on the same focal plain. Weird.
Yeah, my exact thought. I suspect the person had very limited time with the lens and was also limited by where they could take it. Since the lens is not expected for many months, this must have been the pre-production show lens.
I think at that distance, the corners must have been roughly in the same plane of focus as the point marked. Still, it would be interesting to have the results confirmed. I didn't personally see anything in the test which I consider controversial, i.e. I believe their conclusions.
Agree, the focus point was on the left side of the tree, the corner doesn't look that far out of the plane of focus.
carstenw wrote:
I think at that distance, the corners must have been roughly in the same plane of focus as the point marked. Still, it would be interesting to have the results confirmed. I didn't personally see anything in the test which I consider controversial, i.e. I believe their conclusions.
In my estimation, that image is not from a healthy copy of the lens. (It probably got sick at Photokina.) Looking at the center of the full resolution image, here, particularly the "Wehrle" text on the side of the truck, I see considerable asymmetry in the blur structure. I'd be amazed if Zeiss released a lens with that much astigmatism that close to the axis, so this is likely the consequence of decentering. (Also, compare the red-white chain in the lower right to the middle left.) I'll chalk that up to the difficulties of manufacturing prototypes and will wait until the lens is shipping before forming an opinion.
Edit--
Just looked at the ZM shot, and it has the same behavior. Odd. Maybe this is how the lens is designed to behave, and what Zeiss meant when they said it would have lower contrast than the Sony FE lens.
JonPB wrote:
In my estimation, that image is not from a healthy copy of the lens. (It probably got sick at Photokina.) Looking at the center of the full resolution image, here, particularly the "Wehrle" text on the side of the truck, I see considerable asymmetry in the blur structure. I'd be amazed if Zeiss released a lens with that much astigmatism that close to the axis, so this is likely the consequence of decentering. (Also, compare the red-white chain in the lower right to the middle left.) I'll chalk that up to the difficulties of manufacturing prototypes and will wait until the lens is shipping before forming an opinion.
Edit--
Just looked at the ZM shot, and it has the same behavior. Odd. Maybe this is how the lens is designed to behave, and what Zeiss meant when they said it would have lower contrast than the Sony FE lens....Show more →
Of course the shot is at F2 but that example is a bit disappointing to me in that it's not really close to what say the RX1 35 Sonnar lens can do wide open. Lens aberrations are a bit more than I would expect. Hopefully, that's due to either the pre-production nature or...?
It's easier to see the problem when you look at the opposite edge of the image in full resolution. That makes it very clear what should be out of focus and what's being effected by other issues.
I agree that it isn't all that controversial for wide open performance, but it would be nice to have a comparison at 5.6.
mikedefieslife wrote:
Why on earth does that review look at corner sharpness at f/2? Especially on something that's not even on the same focal plain. Weird.
I think the "goal" simply was to show that the Loxia does perform better and does not smear the corners like other lenses do at wide open.
The "test" does not cover a whole lot of ground but I think wide open tests reveal more than a stopped down test that would probably mask off some of the wide open performance deterioration that the ZM 35/2 exhibits on the A7/r sensors. In that aspect the difference is clearly in favor of the Loxia lens and I do think that Zeiss knows exactly what they are doing with the Loxia line.
They can't please the FM crowd with such a simple test - but then again, who can?
I tend to agree with the learned KK (not that others are not learned as well :-). The ZM 35 f:2.0 failed on the A7R, in a binary way, meaning that problems ruined shots beyond repair, and that in far too many sets of circumstances. The choice of a corner crop of an infinity shot wide open simply reflects the choice of the most unfavorable parameters, where the lens sits closest to the sensor. The intent is to show how much performance is improved, and that goal is achieved IMHO. Again in a binary way, the Loxia "works" on the A7R whereas the ZM 35 f:2.0 does not.
Being an old fart of a rather mistrustful nature ( at least, for what concerns marketing in photo business ) I'm not so optimistic as KK and philber. I would be very surprised if the Loxia 35 performed appreciably better than the ZM35/2, everything else being equal. Possibly, in-camera raw correction will fix the color shading issue. Let's wait and see what really happens with smearing and/or lens inherent softness.
I think this test just confirms my own theory that the Loxia line is not optimized for the A7 family but for what Zeiss knows is coming next. Knowing that the ZM 35 would have produced a perfect image in the selected crop if mounted on a Leica M as intended, the Loxia is certainly a step forward but far far from perfect. I am sure Zeiss are very well able to design and manufacture a lens that works much better than this Loxia on the A7, and the reason they didn't in my opinion can only be that they know something we don't.
artur5 wrote:
Being an old fart of a rather mistrustful nature ( at least, for what concerns marketing in photo business ) I'm not so optimistic as KK and philber. I would be very surprised if the Loxia 35 performed appreciably better than the ZM35/2, everything else being equal. Possibly, in-camera raw correction will fix the color shading issue. Let's wait and see what really happens with smearing and/or lens inherent softness.
It already does, look at the results. Day and night. I am not sure if I dare hope that the corners will be excellent wide open, but the ZM is for me completely unacceptable, and the Loxia is an option.
carstenw wrote:
Or that the size and cost constraints made it impossible. Look at the Otus lenses for "perfect" Zeiss designs.
Could very well be, but look at the ZM on the M240. It is excellent, small, and not expensive. The FE 35 is also very good, so it is doable IMHO.
Now if future sensors will feature the same glass thickness, and Zeiss were too lazy to make a better lens, I don't think they will sell a lot of these Loxia.
carstenw wrote:
It already does, look at the results. Day and night. I am not sure if I dare hope that the corners will be excellent wide open, but the ZM is for me completely unacceptable, and the Loxia is an option.
-- this might help the discussion : http://www.verybiglobo.com/photokina-2014-zeiss-loxia-story/
I have read that before, although the Update section was new. I don't see anything which specifically addresses the sharpness of the Loxia 35 in the corners, unless those unmarked crops are corner crops. The ZM is clearly not good on the Sonys.
Tariq Gibran wrote:
I think the question to be answered with this F2 example is if the ZM version shows this amount of lens aberrations wide open on a Leica or not.
+1; Cosina seems to be able to make WA's that work on the A7.
edwardkaraa wrote:
I think this test just confirms my own theory that the Loxia line is not optimized for the A7 family but for what Zeiss knows is coming next. Knowing that the ZM 35 would have produced a perfect image in the selected crop if mounted on a Leica M as intended, the Loxia is certainly a step forward but far far from perfect. I am sure Zeiss are very well able to design and manufacture a lens that works much better than this Loxia on the A7, and the reason they didn't in my opinion can only be that they know something we don't....Show more →
