The MTF's from Zeiss which are at infinity distance show that the 21 at f2.8 is sharper than the 25/2 at f2 in the center.
Roger's test results show the opposite is true at closer 15 feet distance. So it would seem that the 25/2 is optimized for shorter range shooting and the 21 is optimized for longer range shooting.
'Absolute corner values ran about 400-450 for the 25mm (about the same corner numbers we see with the 21 and 35 f2)'
That is a quite unequivocal finding based on no fewer than nine copies, no less - thanks for a tour de force analysis, Roger.
The lens, like many new wide Zeiss efforts, is aimed at reportage and street use, short distances and close ups...which explains the fine bokeh and well-controlled focus fade.
For infinity, we have the MTF charts, kindly reproduced above...these show a slightly different story - wide open the 21mm is clearly better - but not many shoot infinty shots at f2-f2.8, if they know anything about field curvature anyway.
The shift in performance from wide open to 'best aperture' is therefore of great interest - and here note the 21mm loses strength, effectively trading off centre quality for a bit better corners...whereas the 25mm shifts up a gear everywhere, and this at f4. That is special indeed.
f5.6 corner data for both the 21mm and 25mm is very welcome if you get to it, even given your focal distance contraints. Zeiss should do so as well, at infinity.
Ron, I agree with the dealer, and see Kilpatrick's fine review of the all-too-similar ZA 24mm f2, for further information on this future-proofing. This lens copped a bad rap for some reason but artaphot showed how good its corner performance really is, given a couple of extra stops.
philip_pj wrote:
Ron, I agree with the dealer, and see Kilpatrick's fine review of the all-too-similar ZA 24mm f2, for further information on this future-proofing. This lens copped a bad rap for some reason but artaphot showed how good its corner performance really is, given a couple of extra stops.
Here is the best corner performance I saw after trying two different samples (EDIT: this may have been from the first lens which was suspected of being de-centered as the right corner looks slightly better than the left. Second sample was similar in the extreme corners). If one looks at the computed MTF - which needs adjusting down to begin with - there really is no fine detail (40 cycle reading in the corner) in the very extreme corners at infinity. For this reason, the ZA 24/2 was a disappointment for me on FF. Results would only get worse with more than the 24MP I tested with. Perhaps there are some "unicorn" versions of this lens out there that I was not fortunate enough to end up with.
Here you have a new review of this lens, with gallery pics that you can download full size.
Choose your language and click on the photo zeiss lens.
Read carefully because vigneting is not the same in laboratory than in real world.
Cheers
Is it just me or does that look as though the right side is better than the left by a smidge? I've read already that the 35 1.4 ZE is being sold a little decentered to some, I hope Zeiss are not getting slack
thrice wrote:
^^ just like the 135/1.8, 85/1.4, 24-70/2.8 etc? Right? Troll.
135/1.8 - perfect (except occasional loose barel, quality testing isnt strong side of Sony)
85/1.4 - CA a lot of it, otherwise decent.. could be better
24-70/2.8 - similar to same lens from Nikon, which means excellent (tho could be bit sharper at wide end in corners)
24/2 - not so sharp a lot of flare (seriously that thing flares like some old Minolta lens) tho they can fix coating during lifetime..
R.Young wrote:
Is it just me or does that look as though the right side is better than the left by a smidge? I've read already that the 35 1.4 ZE is being sold a little decentered to some, I hope Zeiss are not getting slack
Might be just light. But yes by tiny bit I would say right does look sharper. Tho nothing that would one noticed unless concentrated on that..
R.Young wrote: s it just me or does that look as though the right side is better than the left by a smidge? I've read already that the 35 1.4 ZE is being sold a little decentered to some, I hope Zeiss are not getting slack
The tree (pine) at right side is closer; also the lighting is less hard, so there is more detail.
wayne seltzer wrote:
Tariq, how was the ZA 24/2 at mid or close range?
Maybe, it too was not optimized for infinity
It performed a bit better at say 150 - 200 feet or so though it did show some CA on high contrast borders. It was almost exactly a year ago that I had the two lenses and, if you recall, I showed the closer test on a building and I would still have expected better in the corners by F8. For other uses where critical detail is not required in the corners at longer distances, I thought the lens was fine.
Mescalamba wrote:
135/1.8 - perfect (except occasional loose barel, quality testing isnt strong side of Sony)
85/1.4 - CA a lot of it, otherwise decent.. could be better
24-70/2.8 - similar to same lens from Nikon, which means excellent (tho could be bit sharper at wide end in corners)
24/2 - not so sharp a lot of flare (seriously that thing flares like some old Minolta lens) tho they can fix coating during lifetime..
Im not trolling, I have Sony Alpha mount camera.
The 85 certainly could be better and it shows bokeh CA wide open. However, I think its certainly better than pretty much any other 85 out there except maybe the Canon 85 1.2 II.
I do wish it had SSM though, after using SSM lenses, I'm a convert, the AF is so much more consistent and faster. I always thought geared lenses are no big deal but SSM is truly marvelous.
Having used zeiss contax, as well as ze, zs, zm and za lenses, I have to say the za lenses are the best zeiss has ever designed and manufactured. The build quality is equal to none and the optical quality is better than any equivalent lens zeiss has ever made in the other lines. The za 24 is without any doubt at least as good as the 25/2, and imho better. I have many infinity landscapes that show perfectly sharp corners, even at 5.6. The trick is in hyperfocal focusing. I think cosina can learn a lot from sony about lens manufacturing.
I wonder if the Zeiss designs are made at the old Minolta factories?
From what I remember reading, the ZA lenses have two serial numbers. The case which is Sony and the internal sealed elements which have a separate Zeiss serial number?
FlyPenFly wrote:
I wonder if the Zeiss designs are made at the old Minolta factories?
From what I remember reading, the ZA lenses have two serial numbers. The case which is Sony and the internal sealed elements which have a separate Zeiss serial number?
Yes, almost certainly.
Re the ZA 24, even with focus bracketing, I was never able to obtain tack sharp corners at longer distances. Perhaps I just got lucky with two poor copies. If so, that does not say a lot for QA.
Looking at images from my ZF.2 35/2 and even the above shot from the new Zeiss 25/2, the color and contrast is more subtle with the ZA 24/2 I had. Somewhere between the best Minolta G lenses and the best manual focus Zeiss 35mm lenses.
Tariq Gibran wrote:
It performed a bit better at say 150 - 200 feet or so though it did show some CA on high contrast borders. It was almost exactly a year ago that I had the two lenses and, if you recall, I showed the closer test on a building and I would still have expected better in the corners by F8. For other uses where critical detail is not required in the corners at longer distances, I thought the lens was fine.
Yes, I remember you did an excellent brick wall building lens test. Wish someone could do that with the 25/2 soon.
I haven't been able to get the f/4 and f/5.6 numbers done on the 25mm yet (I got handed a sudden project to test at 50mm today - but you'll like hearing about that one).
It did occur to me, though, that I could at least go out and use our "infinity target": a ridge about 40 meters away with a treeline about 100 meters behind that. Not very scenic, but maybe helpful. I took shots with the 25 at f2; 2.8; 4; 5.6 and 8 and for comparison the 21mm (same shooting spot so slightly different framing) at 2.8;4;5.6 and 8. I think posting downsized jpgs is useless for any detail comparison so I've posted the at 100% here: http://www.pbase.com/rcicala/zf25mmf20&page=all
Feel free to downloFad if you find them useful. At a quick glance, and after playing with the lenses around the shop today I agree with the previous comments: the 25mm seems tuned for closer work and doesn't do quite as well at distance, although it's still quite good in my mind. I'm guessing perhaps that Zeiss is already thinking the cinema folks are going to love the cp.2 version -- and cinema folks don't shoot at infinity much.
