I was not trying to be misleading or anything like that. I understood the question was about the aberrations visible on the truck in the center of the image. My answer was not at all, which is the correct answer. I challenge anyone to prove me wrong. However, if you guys mean the corner crop, I am pretty sure the ZM will be much better than that on the M240 and will not show this kind of aberrations, but I wouldn't have answered not at all. This said, the ZM at f/2 goes slightly soft in the corners and it also shows some veiling haze in zone C mostly, but this is how it behaves on film as well. I own the lens and use it everyday, so I know what I'm talking about.
Henrik, it would be great to see you in this part of the world
The lens aberrations I was referring to are the ones near the center. Many of the details of the cars in the parking lot in that area and even a bit lower down/ closer appear to be sharp, leading me to think perhaps they are not out of focus. I guess we will not really know anything definitive until the lens ships in a few months and more thorough tests are conducted.
that's what i was talking about too looking at the loxia shot. the cars in the lot are out of focus, but just barely. this leads to funky aberrations with the m9 + zm 35/2 as well. it's a very odd shooting situations though – the lens is wide open, the focus distance is about 15m, there is direct bright sunlight all over the frame, and we're looking at something at around 30-50m.
i'm not saying the zm isn't better on the m9, just that it shows the same kind of unattractiveness on a slightly smaller magnitude in such situations.
That explanation makes sense I guess as the leaves which are claimed to be the point of focus do not show the aberrations. It's a strange effect though. I suppose it has something to do with the Zeiss tendency to depict greater dof with wide angle lenses at any given f-stop than one might normally expect as compared to other lenses (so the cars show unexpected detail but the aberrations exist due to still being slightly oof).
Sep 28, 2014 at 10:41 PM
Steve Spencer Offline • • • • • • • Upload & Sell: On
If I understood the Suede's comments right, which maybe I didn't, the Sony cameras may have a flaw in the sensor cover that is distinct from its thickness. It seems they may have cheaped out in the glass and bonding materials and should have used better coatings--perhaps that is why the cameras are fairly prone to sensor flare. If that observation is correct, then we can expect that even if a lens has been adjusted to optimally correct for the sensor glass thickness, then the cover glass materials themselves may still cause some problems. This situation would lead to a few conclusions:
First, if you have a Sony A7(x) camera, a Loxia lens that has been adjusted for the cover glass thickness should perform a lot better than a ZM lens that will underperform because of the the sensor glass thickness. For users of these cameras Loxia lenses would be a nice boost in performance over ZM lenses.
Second, if a Loxia lens is used on a Sony A7(x) camera and it is compared to a ZM lens on a Leica M camera and even if both lenses are optimally adjusted for sensor glass thickness, they might not show equal results. In fact, it seems quite likely they won't. The sensors will be different in a lot of ways. They will have different resolutions; they will have different signal/noise properties; they will have different dynamic ranges; and importantly for this conversation they will have different cover glass materials and one might have better materials than the other. I believe Zeiss that the Loxia lenses will be adjusted for the cover glass thickness of the Sony cameras, but there is nothing Zeiss or anyone but Sony can do about materials used in the sensor cover glass. So Loxia lenses might not do as well as ZM lenses on Leica cameras in some respects because of the materials in the cover glass rather than the thickness of the cover glass. They might do better (and almost certain will in some aspects) because of other properties of the sensor in which the Sony cameras might be better than the Leica camera's sensor. At this point I don't think we even know if the materials used for the Sony cover glass are indeed worse than those used for the Leica cover glass (although given the sensor flare issues this seems likely). In short, comparing ZM on Leica to Loxia on Sony is going to be hard to sort out. I am not sure it will be that useful. There are just too many ways the cameras and lenses differ.
Third, as Sony makes future cameras the performance of some lenses (such as the Loxia lenses) might well improve even if they keep the cover glass the same thickness. It seems that if Sony just uses better materials and maybe even just better coatings on the cover glass lenses designed for the Sony sensor (including the Loxia lenses) might improve noticeably and you might see a lot less sensor flare too. So, I doubt Edward is right in the specifics that Sony will make the cover glass thinner, but I think and hope he is right in a broader sense and that in future cameras Sony makes the cover glass better and lenses like the Loxia lenses perform better on those new cameras than they do on the current cameras.
Without entering into specific arguments, because I have no knowledge of optics at all, the conclusion to which I've arrived is that when you guys say that the filter stack is there for a reason, I believe that the ultimate reason is that they (Sony/Fuji/Oly etc) want it to be so.
IMHO if sensor manufacturers had diverted many years ago their main resources and effort to make sensors which behaved like film, it's very probable that nowadays we wouldn't need any filter stack at all.
To be honest, I really loved my cameras that had very weak to no AA filter: Canon 1Ds original, then 1DsII, and much later on, Leica M9 and M240. I never understood the need to blur the image in order to avoid a little bit of moire. My Sony A900 was really horrible in this regard, very strong AA and very thick sensor cover that killed the performance of any WA in the borders and corners, even Sony's own Zeiss glass. I don't think the A7 has a strong AA filter. In fact it may be very weak, as the effects are not visible, and 24 mp do not need that much AA anyway. Which makes it even more absurd to have such a thick glass cover, unless the effect is there on purpose, to screw M glass owners
Steve Spencer wrote:
If I understood the Suede's comments right, which maybe I didn't, the Sony cameras may have a flaw in the sensor cover that is distinct from its thickness. It seems they may have cheaped out in the glass and bonding materials and should have used better coatings--perhaps that is why the cameras are fairly prone to sensor flare. If that observation is correct, then we can expect that even if a lens has been adjusted to optimally correct for the sensor glass thickness, then the cover glass materials themselves may still cause some problems. This situation would lead to a few conclusions:
First, if you have a Sony A7(x) camera, a Loxia lens that has been adjusted for the cover glass thickness should perform a lot better than a ZM lens that will underperform because of the the sensor glass thickness. For users of these cameras Loxia lenses would be a nice boost in performance over ZM lenses.
Second, if a Loxia lens is used on a Sony A7(x) camera and it is compared to a ZM lens on a Leica M camera and even if both lenses are optimally adjusted for sensor glass thickness, they might not show equal results. In fact, it seems quite likely they won't. The sensors will be different in a lot of ways. They will have different resolutions; they will have different signal/noise properties; they will have different dynamic ranges; and importantly for this conversation they will have different cover glass materials and one might have better materials than the other. I believe Zeiss that the Loxia lenses will be adjusted for the cover glass thickness of the Sony cameras, but there is nothing Zeiss or anyone but Sony can do about materials used in the sensor cover glass. So Loxia lenses might not do as well as ZM lenses on Leica cameras in some respects because of the materials in the cover glass rather than the thickness of the cover glass. They might do better (and almost certain will in some aspects) because of other properties of the sensor in which the Sony cameras might be better than the Leica camera's sensor. At this point I don't think we even know if the materials used for the Sony cover glass are indeed worse than those used for the Leica cover glass (although given the sensor flare issues this seems likely). In short, comparing ZM on Leica to Loxia on Sony is going to be hard to sort out. I am not sure it will be that useful. There are just too many ways the cameras and lenses differ.
Third, as Sony makes future cameras the performance of some lenses (such as the Loxia lenses) might well improve even if they keep the cover glass the same thickness. It seems that if Sony just uses better materials and maybe even just better coatings on the cover glass lenses designed for the Sony sensor (including the Loxia lenses) might improve noticeably and you might see a lot less sensor flare too. So, I doubt Edward is right in the specifics that Sony will make the cover glass thinner, but I think and hope he is right in a broader sense and that in future cameras Sony makes the cover glass better and lenses like the Loxia lenses perform better on those new cameras than they do on the current cameras. ...Show more →
That was my take away as well. It's worth noting that in the past, theSuede has also said that Leica used very cheap/ poor materials for their cover glass as well. Perhaps that has changed with the M240?
artur5 wrote:
...I have no knowledge of optics at all, the conclusion to which I've arrived is that when you guys say that the filter stack is there for a reason, I believe that the ultimate reason is that they (Sony/Fuji/Oly etc) want it to be so.
So they spent money developing the materials and design of the filter stack and the manufacturing process to fix it to the sensor, because they wanted to have several mm of refractive material that makes lens design more difficult?
The ultimate reason why the filter stack exists, is to filter the light hitting the sensor, otherwise you'd get all sorts of crazy effects from infra-red and ultraviolet light that you wouldn't see through an optical viewfinder!
artur5 wrote:
IMHO if sensor manufacturers had diverted many years ago their main resources and effort to make sensors which behaved like film, it's very probable that nowadays we wouldn't need any filter stack at all.
If that had happened there would have probably been a lot of wasted effort as digital sensors are just not suited to being hit at low angles. Everything causes problems, from the filter stack to the CFA, microlenses and pixel structure itself.
Here's a thought, and my knowledge of optics is zilch. If a thinner cover that can do just as well as a thicker cover can, it seems that if Sony moved the sensor toward the lens mount by the difference in thickness it would not degrade the lens performance. In saying this I'm assuming lenses are designed to focus on the face of the cover glass and not on the sensor face.
And here's another question: while everyone is measuring the stack thickness is anyone checking the distance from the sensor face to the lens mount? Is the distance the same on all cameras, Nikon, Sony, and Canon?
Sep 29, 2014 at 10:17 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
john_edwards wrote:
Here's a thought, and my knowledge of optics is zilch. If a thinner cover that can do just as well as a thicker cover can, it seems that if Sony moved the sensor toward the lens mount by the difference in thickness it would not degrade the lens performance. In saying this I'm assuming lenses are designed to focus on the face of the cover glass and not on the sensor face.
And here's another question: while everyone is measuring the stack thickness is anyone checking the distance from the sensor face to the lens mount? Is the distance the same on all cameras, Nikon, Sony, and Canon?...Show more →
I don't think your assumption about where lenses are designed to focus is right. I believe they are designed to focus on the sensor not the cover glass. The problem is that sometimes the cover glass interferes with good focus on the sensor.
The distance from the sensor face to the lens mount is called the registration distance and it varies with different types of lenses. For example a native E mount lens has a registration distance of 18mm, whereas a Canon EF mount lens has a registration distance of 44mm. That is why you need an adapter that is 26mm long to use a Canon EF lens on an E mount camera. Just google "camera registration distance," and you will find a list for many types of cameras.
john_edwards wrote:
Here's a thought, and my knowledge of optics is zilch. If a thinner cover that can do just as well as a thicker cover can, it seems that if Sony moved the sensor toward the lens mount by the difference in thickness it would not degrade the lens performance. In saying this I'm assuming lenses are designed to focus on the face of the cover glass and not on the sensor face.
And here's another question: while everyone is measuring the stack thickness is anyone checking the distance from the sensor face to the lens mount? Is the distance the same on all cameras, Nikon, Sony, and Canon?...Show more →
Actually Sony would have to do that, otherwise the lenses won't focus to infinity.
Matt Grum wrote:
So they spent money developing the materials and design of the filter stack and the manufacturing process to fix it to the sensor, because they wanted to have several mm of refractive material that makes lens design more difficult?
The ultimate reason why the filter stack exists, is to filter the light hitting the sensor, otherwise you'd get all sorts of crazy effects from infra-red and ultraviolet light that you wouldn't see through an optical viewfinder!
If that had happened there would have probably been a lot of wasted effort as digital sensors are just not suited to being hit at low angles. Everything causes problems, from the filter stack to the CFA, microlenses and pixel structure itself. ...Show more →
I think it was mentioned here earlier, but IMO Sony simply implemented the D800(E)/D810 sensor in the A7R camera without changing anything in the sensor array including the glass cover on top of the sensor. This is why older SLR lenses and DSLR lenses work so well in the A7 series whereas some rangefinder lenses cause issues.
I wonder if the Sony sensors are just more reflective and prone to veiling flare? I think the early MFT Oly pen sensors were made by Sony and there was a substantial amount of veiling flare with the Wide angles--even OMZ lenses and not RF:
Michael Gordon wrote:
I wonder if the Sony sensors are just more reflective and prone to veiling flare? I think the early MFT Oly pen sensors were made by Sony and there was a substantial amount of veiling flare with the Wide angles--even OMZ lenses and not RF:
Guys, I got my Loxia 50 today, and took some shots. I was going to post and brag, but that was before I saw that Charlie Shugart had passed away. Somehow now it doesn't feel that important any more. Tonight will be my minute of silence for a great person.
Sep 30, 2014 at 01:01 PM
Steve Spencer Offline • • • • • • • Upload & Sell: On
philber wrote:
Guys, I got my Loxia 50 today, and took some shots. I was going to post and brag, but that was before I saw that Charlie Shugart had passed away. Somehow now it doesn't feel that important any more. Tonight will be my minute of silence for a great person.
philber wrote:
Guys, I got my Loxia 50 today, and took some shots. I was going to post and brag, but that was before I saw that Charlie Shugart had passed away. Somehow now it doesn't feel that important any more. Tonight will be my minute of silence for a great person.
What ! Where did you hear that ? That is really bad news
