edwardkaraa wrote:
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....Show more →
Build quality ZF lens vs ZA. Seriously? Full-metal lens vs mix of plastic, rubber and at best aluminium alloy?
Btw. that nice focus hold and MF/AF switch on 24-70mm f2.8 is held there by double-sided tape. Few ppl found out after it fell off. 135mm f1.8 loosing its barel is quite known issue. And ocassional dead SSM isnt something rare (ZA lens included, or at least these three which has it).
Nowhere near Nikkors as far as build quality goes, or Canon Ls. Not mentioning lack of weather sealing..
I hope Sony will do some "remake" of these lens which will include SSM for all ZA lens and weather sealing. As for now, only sealed lens is kit for A77.
RCicala wrote:
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 are correct: 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. ...Show more →
Thank you Roger. Those are very helpful. That sure is a lot of lenses you have on your plate for testing!
I have recently been testing the ZF.2 35/2 and that lens seems remarkably detailed at medium to longer distances - even into the extreme corners by F8 (FF 24MP a900). I'm a bit surprised by the 25/2 results you got with the tree line. If that's where the focus point is, those trees and the tower look pretty soft to my eyes and that's not even in the corners. This would also lead me to believe the new Zeiss 25/2 must be optimized for closer distances if this is the expected performance.
atran wrote:
looking at this image I think the corner is pretty good by f/8 however I am not sure if this is infinity focus though. What do you guys think ?
This subject matter looks to be fairly close as compared to a typical vista type infinity shot, but it looks damn good at that distance. I am curious if the top corners did contain anything detailed, if the resolution fall-off there would be dramatic.
atran -- I can't tell anything about the corners -- the upper two are blue sky. The lower two are OOF pavers, looking pretty poor from what seems to be recovered vignetting from those lower corners. The center of the image looks very good, but that's what I expect from a decent Zeiss lens.
Roger -- I appreciate your knowledge and help, and I've loved your articles. . . but I found the f/2 image to be awful, on up through f/4. Even the f/8 upper ridge tree branches don't look acceptable to me in upper center (although the middle ground is decent), and especially unacceptable on the upper right and left sides before even getting to the edges. I don't find the far distance to equal infinity -- as I've seen some definite difference in WA focus in my area, where I have sharp visible details about 4 miles away, and can compare to others nearly 1/2 mile away at apertures below f/5.6. I'm just saying that 40 or 100 meters is far short of infinity focus at wider apertures.
Personally, I would be hoping for better outdoor resolution. Same for the 21mm examples. I like to think of myself as a pixel peeper, but I'm no technician when it comes to testing. But I might be missing something about these examples, so I hesitate to weigh-in.
I'm sure you know expectations are running very high for this lens!
Much appreciated, Roger. And please don't let us interfere with your business.
It looks like the focal distance is the large tree in the far centre of the image, but it will be so close to infinity as to not matter (certainly not on the focus ring), and the distant aircraft in the 25/8 image looks in good focus.
The 21mm has much better CA control, but this is a tough test. It shows much less improvement with stop down than the 25mm, but is a good lesson in using small apertures nonetheless. Tiny right edge detail is still resolved at f2.8 just as it is at f8, but with much less contrast. Same with the image centre.
The 25mm f2.8 image is truly troubled everywhere, and the smaller apertures show much more improvement than the 21mm does. By f8 the centre of the 25mm is quite good. On the right edge the 25mm f8 image looks to have around the same level of detail as the 21mm, which is a poor result given the significant extra magnification.
It's just another data point, but still very valuable, and thanks again - your work is the best.
Thanks for the ZA 24/2 images, Tariq. The extreme edge of the crops don't look sharp at all but at least you can observe the performance drop-off in each of them. I was looking for curvature as an explanation as maybe each corner is closer than the centre content, do you recall looking at the centre distance of these images, if so how were they? Did corners clean up with less than infinity focus?
I confess I don't know how to reconcile the MTF (Zeiss's own, no less) with the images Roger posted. Those charts of the ZA 24/2 look very unreliable (not just the level) but do show poor corners are to be expected.
Is Zeiss no longer interested in middle ground to distant compositions? Maybe the 25/2.8 is worth a good look, from what I have read here. The 24/2 looks like a fine lens re price, SSM and overall image quality.
Ed, I seldom use infinity on the ring, why waste in-focus content, of which there is plenty with these wides. I would however expect all content to be pretty good at infinity. Do you think curvature shapes focus into the distance for edges with these lenses you have tried?
philip_pj wrote:
Thanks for the ZA 24/2 images, Tariq. The extreme edge of the crops don't look sharp at all but at least you can observe the performance drop-off in each of them. I was looking for curvature as an explanation as maybe each corner is closer than the centre content, do you recall looking at the centre distance of these images, if so how were they? Did corners clean up with less than infinity focus?
I confess I don't know how to reconcile the MTF (Zeiss's own, no less) with the images Roger posted. Those charts of the ZA 24/2 look very unreliable (not just the level) but do show poor corners are to be expected. ...Show more →
Hi Philip. The central area with those infinity shots is sharp. As I mentioned, I also performed a closer test, which I posted here a year ago, of a building and the corners never fully sharpened up by F8 even with focus bracketing. Edward has mentioned that he achieved sharp corners with his copy of the ZA 24 by focusing at a closer distance but I never saw that with the two copies of the lens I tested.
I tried to find that thread in a search, Tariq, but got a web certificate for some reason. I forgot about it back then, based partly on your comments.
I understand your disappointment now, but how to account for the glowing reviews I linked?
Two samples being poor is unlikely, but if both were early releases perhaps it's possible? It is interesting that Kilpatrick did not want to buy this one initially, until he looked at it in more detail later on.
RCicala wrote:
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 are correct: 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. ...Show more →
Thanks so much Roger for taking the time to shoot and post these full size test pix.
Wow, I have never seen a Zeiss lens suck this bad at infinity and med to far distance.
The edge of the frame, not even the corner falls of a cliff like the MTF shows even at f8. !
I guess this lens is not FLE design as it clearly works better at closer distances.
My 24G has good corners by f5.6 and performs equally well at all distances.
The ZF 25/2.8 is much better across the frame too and a lot less money.
Looks like we need Herr Schuster to come out of retirement and design us the next wide angle Zeiss lens with performance like the mighty 21.
Thanks again Roger!
I'm am not a "connaisseur" but in my opinion tehe Zeiss 25mm ZE is a very good lens.
¿Why to make a photograph at infinity, aperture 2? We will see corners plenty of chromatic aberrations.
Plaese give a look at this pic: http://www.digitalcamaralens.com/Html/Objetivos/Zeiss/Distagon%2025%202%20ZE/Galeria/IMG_0801.jpg
You can download full size by clicking on the pic.
Focus is at 35 meters aprox (bell tower). Aperture 2.
Is not bad at all.
(Church of Colonia Güell, Barcelona. By Gaudí)
Mescalamba, you seem to be bitter with Sony, so no comments.
Fly, so lack of weather sealing on ZA is a problem, but lack of it on ZE is acceptable?
Philip, in my own experience with the copy of the ZA that I had, there was no problem at infinity from 5.6 onwards when focused about -5 micro adjustment. The field curvature of the ZA24 is in a U shape, which means that when center is in focus the corners are back focused. This is a problem at infinity in particular. But if you focus as you describe, I am pretty confident there should be no problem.
wayne seltzer wrote:
Thanks so much Roger for taking the time to shoot and post these full size test pix.
Wow, I have never seen a Zeiss lens suck this bad at infinity and med to far distance.
The edge of the frame, not even the corner falls of a cliff like the MTF shows even at f8. !
I guess this lens is not FLE design as it clearly works better at closer distances.
My 24G has good corners by f5.6 and performs equally well at all distances.
The ZF 25/2.8 is much better across the frame too and a lot less money.
Looks like we need Herr Schuster to come out of retirement and design us the next wide angle Zeiss lens with performance like the mighty 21.
Thanks again Roger!
Sergi2, what sharpening settings are you applying in ACR? It looks terrible in my opinion, but not because of the lens, but because of the demosaicing artefacts. The images looks like they are built up of "flakes", so that the real resolution isn't seen.
I suggest you set the sharpening in ACR to 0 and sharpen with USM 0,2 – 200% in PS instead.
philip_pj wrote:
I tried to find that thread in a search, Tariq, but got a web certificate for some reason. I forgot about it back then, based partly on your comments.
I understand your disappointment now, but how to account for the glowing reviews I linked?
Two samples being poor is unlikely, but if both were early releases perhaps it's possible? It is interesting that Kilpatrick did not want to buy this one initially, until he looked at it in more detail later on.
I find Kurt's lens reviews to be pretty much spot on with my experience. If you look at his FF corners of the ZA 24/2 taken at infinity, I think you will see they are fairly close to my results - no fine detail (40 cycles on MTF) in the corners and the CA issue. Different folks have different expectations of what they consider sharp I guess.
Seriously? Full-metal lens vs mix of plastic, rubber and at best aluminium alloy?
135mm f1.8 loosing its barel is quite known issue. And ocassional dead SSM isnt something rare (ZA lens included, or at least these three which has it).
!