Toothwalker wrote:
I know because that is what Zeiss says when you ask them. It was actually a superfluous question, because the Zeiss lens sheets always show the MTF at the magnification for which the lens is optimized (and in the case of the Makro Planars at additional magnifications).
However, they paid particular attention to the variable air spaces to create a lens that excels over its entire focusing regime, apart from the corners at large apertures. I would not be surprised if PZ and the like go crazy.
All one must do is compare the MTF's of the Zeiss 21 to the 25/2 and see the much worse corner performance of the 25/2. This is part of the reason, along with some poor examples, that I think the question remains about the 25/2's performance in the corners at infinity. Even the Zeiss 25/2.8 has better corner performance per the MTF's.
Tariq Gibran wrote:
All one must do is compare the MTF's of the Zeiss 21 to the 25/2
No. To answer the question at hand, all one must do is compare the MTFs of the 2/25 at infinity and at close(r) focus. Since the latter is not available, we just need to trust the word of Zeiss.
Toothwalker wrote:
No. To answer the question at hand, all one must do is compare the MTFs of the 2/25 at infinity and at close(r) focus. Since the latter is not available, we just need to trust the word of Zeiss.
The question at hand for me is: does the 25/2 have an issue with delivering sharp corner performance at infinity. As I posted above, the MTF's seem to indicate it does, particularly in comparison to the other Zeiss lenses I noted.
Toothwalker wrote:
The Sala Oval del Palau Nacional de Montjuïc answers your question.
An interior shot showing relatively close decent corners does not answer the question for me as to what will happen with distant mountains, trees, etc.in the corners.
Tariq Gibran wrote:
The question at hand for me is: does the 25/2 have an issue with delivering sharp corner performance at infinity. As I posted above, the MTF's seem to indicate it does, particularly in comparison to the other Zeiss lenses I noted.
OK, but that is a different question than the question whether or not the 2/25 has been optimized for infinity.
So far the various testers seem to get very different results with the 2/25. I presume sample variations are not that big, and that the best results shown so far demonstrate what is possible with proper mechanical alignment, focusing, and DOF considerations. To be certain, I just need to wait until I have my own copy.
Tariq Gibran wrote:
An interior shot showing relatively close decent corners does not answer the question for me as to what will happen with distant mountains, trees, etc.in the corners.
Toothwalker wrote:
This interior is far enough to count as infinity.
Issues such as field curvature and increased distance could result in the possibility that something such as these corners at a closer distance could be decent whereas subject matter further away might not. So, field curvature is one issue. The decreased magnification of soft corners at further distances is another.
Toothwalker wrote:
OK, but that is a different question than the question whether or not the 2/25 has been optimized for infinity.
So far the various testers seem to get very different results with the 2/25. I presume sample variations are not that big, and that the best results shown so far demonstrate what is possible with proper mechanical alignment, focusing, and DOF considerations. To be certain, I just need to wait until I have my own copy.
jorge has already shown that the 25mm is sharp into the corners barring the last 1-2mm so i think that all the tests showing significantly worse corners are clearly erroneous.
simonw wrote:
jorge has already shown that the 25mm is sharp into the corners barring the last 1-2mm so i think that all the tests showing significantly worse corners are clearly erroneous.
cheers, simon w.
It is the last 2 mm that concern some. We can get sharpness across the frame at a FOV corresponding to a 28 mm lens and a 17 MP 5DII.
simonw wrote:
jorge has already shown that the 25mm is sharp into the corners barring the last 1-2mm so i think that all the tests showing significantly worse corners are clearly erroneous.
cheers, simon w.
I don't think so. Wayne for example knows how to test lenses. But it's still not clear to me, whether the soft corners we see are the result of FC or not. But this is easily testable with lifeview focus on the corner.
hmm. ok. i thought that jorge's results all looked pretty good to me so i assumed that his were the one's to beat (as it were). i think that having the lens on an adapter throws in one variable too many for my tastes when looking at wayne's examples (and we have had several examples now where people have been trying to compare F2.8 with F8).
i'm enjoying shooting with the 25mm personally which i guess is really all that matters in the end. it is very much a modern zeiss lens and sits well with the 50mm F2 and 100mm F2 as a new lens trinity (joining the more traditional F1.4 group of 35mm, 50mm and 85mm). one thing that i have found is that the bokeh quality is very pleasing at wider apertures and the lens is such a tactile experience that i have found myself dragging along my gitzo and spending time just setting up and shooting.
i guess i'm just disturbed that people are already making up their minds (and dismissing) this lens after such a small sampling of what this lens can do has appeared. it is not as if pure sharpness is the only quality that can be used to judge a lens (and if it is then surely the canon tse 24mm would be the way to go).
I looks like it is a great lens for certain usecases (like street photography), but for classical landscape photography I would probably prefer the 21 ZE (or the 24 TSE II).
simonw wrote:
hmm. ok. i thought that jorge's results all looked pretty good to me so i assumed that his were the one's to beat
i'm enjoying shooting with the 25mm personally which i guess is really all that matters in the end. it is very much
i guess i'm just disturbed that people are already making up their minds (and dismissing) this lens after such a small sampling of what this lens can do has appeared. it is not as if pure sharpness is the only quality that can be used to judge a lens (and if it is then surely the canon tse 24mm would be the way to go).
Enjoy your lens, Simon! Fact is, I agree with you that sharpness is overrated as far as lens performance goes. This is because it is "objective" and measurable, whereas colours for example, are not. I remember when the 35 f:1.4 was released, Lloyd Chambers went on about a haze that made it useless wide open. That lead to the lens being dismissed by many. I did not cancel my order, got the lens, found it to be my most enjoyable ZE, and notice that its reputation is steadily growing. Even LC has published that it is sharp wide open. One day MM Zeiss will see fit to ship my 25, and I expect to form my own opinion, and post supporting examples. My advantage over others in this exercise is that I am pursuing neither readership, nor following or consensus, and do not think less of those who disagree with me.
That said, I believe that Wayne's shots prove that "there is something there". Question is: how much does it matter? And the answer to that must be individual, rather than judgemental.
I think all most around here want to know are the capabilities and limitions of this lens before spending such a large amount of $$ on it to make sure it suits their specific uses. The more examples and tests we see, the more informed we all become.
With all these corner discussions, I thought I'd take a look how mine performs. This is not at infinity, just a shot out of my window. I'll check longer distances later on. But so far I like this lens a lot. The corners are not perfect but certainly good enough for this case.
I was able to go back to Stanford church and take some more test shots against the church wall to see if I optimized the focus for the corners how would they look along with the rest of the frame. I will post these and some infinity type landscape comparison shots with the 25/2 and the 21 which show that dulled corner problem in the foreground like I did on that beach shot I posted before this time I made sure the 25/2 was at f8. I also took some night time street shots with it and my 24G and I would like to post them later too and talk about their differences.
Concerning the corners I was not able to significantly make them better when I focused just on them. So I am not sure if it is curvature of field affecting these extreme corners.
If it is field curvature which curves away from you, what can you do when you are focused at infinity,especially if the lens has an infinity stop like this one.
Simon, I am not trying to trash the lens, just do some testing and comparing to my 21 for landscape type shooting and figure out any flaws as well as the strengths. It is a great lens but not perfect,but pls. enjoy your copy and if you can take infinity shots and find better corners pls. go ahead and post them.
Everyone has their own opinions on whether this extreme corner performance matters or not to them and their type of shooting. On top of that some people either may or may not have other zeiss lenses like the 21 or original 25/2.8 which influence whether they will buy this lens or not.
These extreme corners are not in usual testing zone of the usual lens testers like photozone so I don't expect the extreme corner issue to show up in the results.They are also not testing at infinity but 50 x 25mm instead.
I also took some night time street shots with it and my 24G and I would like to post them later too and talk about their differences.