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Thread: GFX microlens discussion at Kasson

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    GFX microlens discussion at Kasson

    I was wondering what you guys think of the thoughts expressed in the following article. I believe Lloyd Chambers also wrote something similar.


    https://blog.kasson.com/gfx-50s/on-m...and-gfx-50r-s/

    https://diglloyd.com/blog/2019/20190...ilmGFX50S.html

    If as Kasson suggested, the issue with the GFX50 is due to the microlenses on the sensor, is the same argument also applicable to the X1D sensor, since they are essentially the same. I haven't shot with GFX50, but I don't think I am seeing the crunchiness or oversharpening that is being discussed. Thoughts, anyone?
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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by P. Chong View Post
    I was wondering what you guys think of the thoughts expressed in the following article. I believe Lloyd Chambers also wrote something similar.


    https://blog.kasson.com/gfx-50s/on-m...and-gfx-50r-s/

    https://diglloyd.com/blog/2019/20190...ilmGFX50S.html

    If as Kasson suggested, the issue with the GFX50 is due to the microlenses on the sensor, is the same argument also applicable to the X1D sensor, since they are essentially the same. I haven't shot with GFX50, but I don't think I am seeing the crunchiness or oversharpening that is being discussed. Thoughts, anyone?
    Only Fuji customized the size of the microlenses on the Sony 50 mp sensor used in the GFX 50S and 50R. The Sony sensor used in the X1D is different in that respect. Fuji’s marketing campaign made a point of emphasizing how it had customized the microlenses, leading to the appearance of sharper images. When I tested the GFX 50 S side by side with the X1D back in early 2017, I did notice that the Fuji files using LR default sharpening settings appeared “sharper” than the X1D files with LR defaults. However, with sophisticated capture sharpening, the X1D files improved very significantly and looked to me more natural. I recall questioning Mr. Kasson at the time about the potential downsides of how Fuji had reduced the size of the microlenses. After all, Hasselblad and Phase had used the same sensor and had never reduced the size of the microlenses. There is generally no free lunch in such matters. Mr. Kasson at the time seemed to have fully bought into Fuji’s secret sauce, and I think he said there was a theoretical possibility of artifacts in some corner cases but it was unlikely to be an issue in practice. He stated that sophisticated capture sharpening could level the playing field somewhat, but it was always better to start with a raw file that was “inherently “ sharper. Now, 2 and 1/2 years later, we are hearing second thoughts from two sources.
    IMO, this is not all that big a deal. Most of the world is in love with oversaturated and oversharpened images.
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    Re: GFX microlens discussion at Kasson

    Ah, I see...thanks for the reply. Makes sense. I always thought that the X1D images were better looking than the GFX, though I am not able to describe why. Now, I know.


    Quote Originally Posted by hcubell View Post
    Only Fuji customized the size of the microlenses on the Sony 50 mp sensor used in the GFX 50S and 50R. The Sony sensor used in the X1D is different in that respect. Fuji’s marketing campaign made a point of emphasizing how it had customized the microlenses, leading to the appearance of sharper images. When I tested the GFX 50 S side by side with the X1D back in early 2017, I did notice that the Fuji files using LR default sharpening settings appeared “sharper” than the X1D files with LR defaults. However, with sophisticated capture sharpening, the X1D files improved very significantly and looked to me more natural. I recall questioning Mr. Kasson at the time about the potential downsides of how Fuji had reduced the size of the microlenses. After all, Hasselblad and Phase had used the same sensor and had never reduced the size of the microlenses. There is generally no free lunch in such matters. Mr. Kasson at the time seemed to have fully bought into Fuji’s secret sauce, and I think he said there was a theoretical possibility of artifacts in some corner cases but it was unlikely to be an issue in practice. He stated that sophisticated capture sharpening could level the playing field somewhat, but it was always better to start with a raw file that was “inherently “ sharper. Now, 2 and 1/2 years later, we are hearing second thoughts from two sources.
    IMO, this is not all that big a deal. Most of the world is in love with oversaturated and oversharpened images.

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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by hcubell View Post
    Only Fuji customized the size of the microlenses on the Sony 50 mp sensor used in the GFX 50S and 50R. The Sony sensor used in the X1D is different in that respect. Fuji’s marketing campaign made a point of emphasizing how it had customized the microlenses, leading to the appearance of sharper images. When I tested the GFX 50 S side by side with the X1D back in early 2017, I did notice that the Fuji files using LR default sharpening settings appeared “sharper” than the X1D files with LR defaults. However, with sophisticated capture sharpening, the X1D files improved very significantly and looked to me more natural. I recall questioning Mr. Kasson at the time about the potential downsides of how Fuji had reduced the size of the microlenses. After all, Hasselblad and Phase had used the same sensor and had never reduced the size of the microlenses. There is generally no free lunch in such matters. Mr. Kasson at the time seemed to have fully bought into Fuji’s secret sauce, and I think he said there was a theoretical possibility of artifacts in some corner cases but it was unlikely to be an issue in practice. He stated that sophisticated capture sharpening could level the playing field somewhat, but it was always better to start with a raw file that was “inherently “ sharper. Now, 2 and 1/2 years later, we are hearing second thoughts from two sources.
    IMO, this is not all that big a deal. Most of the world is in love with oversaturated and oversharpened images.
    What you say about the microlenses in the X1D vs the GFX 50x is true, as far as I know. I believe what you have said about my thoughts about the GFX 50S at the time of its introduction is a mischaracterization. I was always aware of the downsides of the small microlenses, and made at least one post in my blog illustrating somewhat increased false color and moire.

    https://blog.kasson.com/the-last-wor...y-a7rii-moire/

    In that post, I said: "We have seen that the GFX sensor produces much sharper images than the a7RII sensor, with both the Fuji native lenses and some selected Zeiss full frame lenses. It is even sharper sometimes on a cycles/pixel basis, not just cycles/picture height. This is probably because of Fuji’s smaller-than-normal microlenses. But there’s a potential downside to all that sharpness: aliasing. If the aliasing occurs with a subject with strong spatial frequency components within a factor of 10 or 20 of the sampling frequency, the result is difference frequency artifacts in the captured image."

    In that post, I also said: "This is an image where the difference is striking. Possibly some focus distance differences were involved, but I could consistently get moire in this area of the striped shirt with the GFX, and hardly any with the a7RII."

    And also: "Netting it out, the GFX is more susceptible to moire, as the earlier testing predicted. But the difference is certainly not night and day."

    If you can document my "fully [buying] into Fuji's secret sauce", please do so. If you can provide a link to where I said it's *always* better to start with a raw file that is inherently sharper, please do that.

    Otherwise, please stop paraphrasing what you think I said on this point.

    It is true that I have become more negative about the GFX 50S small microlenses since getting the GFX 100, but that's not about the absolute microlens size in isolation from the pitch -- the GFX 100 microlenses are only slightly larger than the GFX 50x ones.

    Jim
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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by P. Chong View Post
    I was wondering what you guys think of the thoughts expressed in the following article. I believe Lloyd Chambers also wrote something similar.


    https://blog.kasson.com/gfx-50s/on-m...and-gfx-50r-s/

    https://diglloyd.com/blog/2019/20190...ilmGFX50S.html

    If as Kasson suggested, the issue with the GFX50 is due to the microlenses on the sensor, is the same argument also applicable to the X1D sensor, since they are essentially the same. I haven't shot with GFX50, but I don't think I am seeing the crunchiness or oversharpening that is being discussed. Thoughts, anyone?
    Lloyd talks about the GFX 100 "oversampling", but in my tests, it doesn't do that with even the worst G-mount native lens at its worst focal length. There is still aliasing visible there, which is prima facie evidence of the lens delivering a projected image to the sensor that contains energy at spatial frequencies in excess of the Nyquist frequency. With the best G-mount lenses, at anywhere near their sharpest apertures, with demanding subjects, there is gobs of aliasing with the GFX 100.



    Jim
    Last edited by JimKasson; 4 Weeks Ago at 06:25. Reason: Add image
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    Re: GFX microlens discussion at Kasson

    Thanks Jim for your explanation.

    In your blog article you showed both the pattern with heavy moire in the center taken by both GFX50R and GFX100. Certainly the effect on the 50R is worse. But the GFX100 is not great either, or in your opinion, this is normal.

    Am I reading correctly that the GFX100 uses normal micro lenses, and not smaller ones in the GFX50RS? Or as the GFX100 being BSI, this comparison is meaningless?What about compared to the X1D? I understand pixel pitch is totally different, so does it make sense to make such a comparison?

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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by P. Chong View Post
    Thanks Jim for your explanation.

    In your blog article you showed both the pattern with heavy moire in the center taken by both GFX50R and GFX100. Certainly the effect on the 50R is worse. But the GFX100 is not great either, or in your opinion, this is normal.
    Yes. It is normal practice to make the microlenses cover about the full pitch. The GFX 50S and GFX 50R were outliers. The GFX 100 returns to conventional practice. We will need cameras with about 1000 MP before we are completely free from aliasing with the lenses that we have today. Note that, with the GFX 100, you can make almost all the aliasing go away if you stop down to f/11, and it completely goes away at f/16.

    Quote Originally Posted by P. Chong View Post
    Am I reading correctly that the GFX100 uses normal micro lenses, and not smaller ones in the GFX50RS?
    Relative to the pixel pitch, yes. In absolute terms, the GFX 100 microlenses are slightly smaller than the GFX 50x ones.

    Quote Originally Posted by P. Chong View Post
    Or as the GFX100 being BSI, this comparison is meaningless?
    Whether the sensor is BSI or not is a second-order effect here. Probably best ignored.

    Quote Originally Posted by P. Chong View Post
    What about compared to the X1D? I understand pixel pitch is totally different, so does it make sense to make such a comparison?
    I have not tested the X1D, but from all the reports I've read it has about 100% effective fill factor, which is the standard practice these days. That makes the X1D microlenses the same size as the GFX 100 relative to the pitch, and about 1.4 times as large linearly (2x the area) in absolute terms.

    Jim
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    Re: GFX microlens discussion at Kasson

    Jim..... your analysis, which I have great confidence in, explains to some extent the softness of my GFX 100 compared to my 50S. I was very used to seeing files that were sharp and was surprised and disappointed at the softness of the files from the 100.

    However, FWIW, the files from my 3100 and the files from my 4150 are similar in sharpness to what I am seeing with my 50s. Of course none of what I am doing approaches the technical approach you are taking - I'm just using my eyes. So what I was seeing from the 100 as compared to 'both' my Phase DBs and my 50s caused me to have some 'real' concern about what was going on under the hood.

    If you ever want files from a 4150 let me know.

    Victor

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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by vjbelle View Post
    Jim..... your analysis, which I have great confidence in, explains to some extent the softness of my GFX 100 compared to my 50S. I was very used to seeing files that were sharp and was surprised and disappointed at the softness of the files from the 100.

    However, FWIW, the files from my 3100 and the files from my 4150 are similar in sharpness to what I am seeing with my 50s. Of course none of what I am doing approaches the technical approach you are taking - I'm just using my eyes. So what I was seeing from the 100 as compared to 'both' my Phase DBs and my 50s caused me to have some 'real' concern about what was going on under the hood.

    If you ever want files from a 4150 let me know.

    Victor
    I think the GFX 100 files are just fine wrt sharpness. I am beginning to form a theory: if the images look sharp at the pixel level, there is aliasing there.

    Thanks for the offer of the 4150 files. I expect a central 33x44 mm section from those files will look the same as the GFX 100 files, but it would be interesting to test. If you're interested, shoot a Siemens Star with a good lens at its optimum aperture from far enough away that you can see aliasing about a quarter to a third of the way out from the center to the rim. The Siemens Star that Zeiss makes is fine. Then get me some raw files.

    Thanks.

    Jim

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    Re: GFX microlens discussion at Kasson

    I'll have to find a Siemans Star first then I'll send you a link.

    Victor
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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by vjbelle View Post
    I'll have to find a Siemans Star first then I'll send you a link.

    Victor
    Victor,
    If you can't find one let me know. I can do it this afternoon and upload the images.

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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by JimKasson View Post
    What you say about the microlenses in the X1D vs the GFX 50x is true, as far as I know. I believe what you have said about my thoughts about the GFX 50S at the time of its introduction is a mischaracterization. I was always aware of the downsides of the small microlenses, and made at least one post in my blog illustrating somewhat increased false color and moire.

    https://blog.kasson.com/the-last-wor...y-a7rii-moire/

    In that post, I said: "We have seen that the GFX sensor produces much sharper images than the a7RII sensor, with both the Fuji native lenses and some selected Zeiss full frame lenses. It is even sharper sometimes on a cycles/pixel basis, not just cycles/picture height. This is probably because of Fuji’s smaller-than-normal microlenses. But there’s a potential downside to all that sharpness: aliasing. If the aliasing occurs with a subject with strong spatial frequency components within a factor of 10 or 20 of the sampling frequency, the result is difference frequency artifacts in the captured image."

    In that post, I also said: "This is an image where the difference is striking. Possibly some focus distance differences were involved, but I could consistently get moire in this area of the striped shirt with the GFX, and hardly any with the a7RII."

    And also: "Netting it out, the GFX is more susceptible to moire, as the earlier testing predicted. But the difference is certainly not night and day."

    If you can document my "fully [buying] into Fuji's secret sauce", please do so. If you can provide a link to where I said it's *always* better to start with a raw file that is inherently sharper, please do that.

    Otherwise, please stop paraphrasing what you think I said on this point.

    It is true that I have become more negative about the GFX 50S small microlenses since getting the GFX 100, but that's not about the absolute microlens size in isolation from the pitch -- the GFX 100 microlenses are only slightly larger than the GFX 50x ones.

    Jim
    I am sure that you told ME personally that it was better to start with a GFX file that needed less capture sharpening because of the smaller microlenses than to try to "compensate" to achieve that level of sharpness by using sophisticated capture sharpening techniques. I distinctly remember the discussion. I am not going to spend a lot of time trying to find it, as I can't recall whether it was an email or a PM on a Forum. It doesn't really matter, because the issue of sharpness is overrated by people who obsess over it.

    However, with all of the work you have done on the GFX over 2 and 1/2 years, I don't ever recall you questioning whether the smaller microlenses was problematic because it would tend to produce oversharpened images. It is strange that this issue is now coming up. It's not like the "secret sauce" is new. And, it's not like there haven't been many GFX files from that sensor for people to examine. I think you said you were surprised by the proliferation of oversharpened images from the GFX that you were seeing online, because GFX photographers were more sophisticated about sharpening than FF shooters. You pointed to the microlenses as the (or perhaps "an") explanation. I have no idea as to whether it is the microlenses, but I think your basic premise is problematic. Do you have any idea as to how many buyers of the GFX 50S and R are former APS-C and FF shooters? Do you have any idea what percentage of them shoot JPEGs and leave it to Fuji to do the sharpening for them? I assume you understand how images that are otherwise properly capture sharpened in their native file size are susceptible to looking oversharpened when they are exported into small JPEGs for the web.
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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by dchew View Post
    Victor,
    If you can't find one let me know. I can do it this afternoon and upload the images.

    Dave
    Thanks. I wouldn't mind having two sets of images...

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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by hcubell View Post
    I am sure that you told ME personally that it was better to start with a GFX file that needed less capture sharpening because of the smaller microlenses than to try to "compensate" to achieve that level of sharpness by using smaller microlenses. I distinctly remember the discussion. I am not going to spend a lot of time trying to find it, as I can't recall whether it was an email or a PM on a Forum.
    Then please stop putting words in my mouth.


    Quote Originally Posted by hcubell View Post
    It doesn't really matter, because the issue of sharpness is overrated by people who obsess over it.
    This is more a discussion of artifacts than of sharpness.

    Quote Originally Posted by hcubell View Post
    However, with all of the work you have done on the GFX over 2 and 1/2 years, I don't ever recall you questioning whether the smaller microlenses was problematic because it would tend to produce oversharpened images.
    I am not saying that the small microlenses are a problem because they encourage oversharpened images. I'm saying that they are a problem because of aliasing. That's a different thing entirely.

    The oversharpening occurs, I believe, because Lr and C1 did not adjust their default sharpening in order to take into account the small microlenses, leading to oversharpened images at the default sharpness settings. You can't blame that on the camera.

    Quote Originally Posted by hcubell View Post
    It is strange that this issue is now coming up. It's not like the "secret sauce" is new. And, it's not like there haven't been many GFX files from that sensor for people to examine.
    It's not just coming up now. I have been on a minor tear about oversharpening in general for the last couple of years, and the GFX 50x images are no exception.

    Quote Originally Posted by hcubell View Post
    I think you said you were surprised by the proliferation of oversharpened images from the GFX that you were seeing online, because GFX photographers were more sophisticated about sharpening than FF shooters. You pointed to the microlenses as the (or perhaps "an") explanation. I have no idea as to whether it is the microlenses, but I think your basic premise is problematic. Do you have any idea as to how many buyers of the GFX 50S and R are former APS-C and FF shooters? Do you have any idea what percentage of them shoot JPEGs and leave it to Fuji to do the sharpening for them? I assume you understand how images that are otherwise properly capture sharpened in their native file size are susceptible to looking oversharpened when they are exported into small JPEGs for the web.
    I'll never be able to test the reason for the proliferation of oversharpened files in general and GFX 50x files in particular. I can only guess. Many of the GFX 50x images that I think are oversharpened are otherwise high-quality images made by working commercial photographers.

    Jim
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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by JimKasson View Post
    Then please stop putting words in my mouth.




    This is more a discussion of artifacts than of sharpness.



    I am not saying that the small microlenses are a problem because they encourage oversharpened images. I'm saying that they are a problem because of aliasing. That's a different thing entirely.


    Jim
    Oh, please. Just go back and reread your blog post. You announce that the small microlenses "made the captured images sharper---astonishingly so, in measurements that I made--- and also made the camera more prone to aliasing." You go on to say that "many, if not most," of the GFX 50S files displayed on the web are "oversharpened," and you link that with the smaller microlenses. Did I also put those words in your mouth? Does "also" not mean "also"?

    Though it's not at the level of the Catholic Church changing its view on birth control, I do find this incipient reassessment of the smaller microlenses mildly amusing.

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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by hcubell View Post
    Oh, please. Just go back and reread your blog post. You announce that the small microlenses "made the captured images sharper---astonishingly so, in measurements that I made--- and also made the camera more prone to aliasing." You go on to say that "many, if not most," of the GFX 50S files displayed on the web are "oversharpened," and you link that with the smaller microlenses. Did I also put those words in your mouth? Does "also" not mean "also"?

    Though it's not at the level of the Catholic Church changing its view on birth control, I do find this incipient reassessment of the smaller microlenses mildly amusing.
    It's perfectly fine to discuss things I said in my blog posts. That's different from saying I said something which I don't remember saying, that seems at odds with my other writings at the time, and for which you have no documentation that I said it.

    Jim

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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by dchew View Post
    Victor,
    If you can't find one let me know. I can do it this afternoon and upload the images.

    Dave
    Dave..... go ahead. I'll have my chart in a couple of days and shoot it with the Rody 90 and then Jim can have a couple of charts to look at.

    Victor

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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by JimKasson View Post
    Thanks. I wouldn't mind having two sets of images...
    Here you go, Jim. IQ4150, sk60xl @ f/8. Don't hesitate to tell me if you need something different, either magnification or anything else. Might take my not-so-zoomy DSL a few minutes to get around to finishing the upload.
    https://www.dropbox.com/sh/oq7j503zy...80ZqK-dwa?dl=0

    Dave

    Note: The metadata says f/11 but that is just the lose nut behind the camera who forgot to change it to f/8.
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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by vjbelle View Post
    Dave..... go ahead. I'll have my chart in a couple of days and shoot it with the Rody 90 and then Jim can have a couple of charts to look at.

    Victor
    Ok, I added the sk90 too. Jim, do me a favor: When you find out Victor's 90hrsw is sharper than my sk90 apo-digitar, you are welcome to tell him but please don't mention it to me.

    Dave
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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by dchew View Post
    Here you go, Jim. IQ4150, sk60xl @ f/8.
    I couldn't open the file in ACR or Lightroom. Even DNG converter choked on it. But I opened it in RD, exported the first green channel, and did the same for some GFX 100 images with the 110/2.

    Pictures here:

    https://blog.kasson.com/gfx-100/iq4-...-same-sausage/

    I would expect that both lenses are pretty much diffraction limited on axis at f/8.

    Jim
    Last edited by JimKasson; 4 Weeks Ago at 13:49.
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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by JimKasson View Post
    It's perfectly fine to discuss things I said in my blog posts. That's different from saying I said something which I don't remember saying, that seems at odds with my other writings at the time, and for which you have no documentation that I said it.

    Jim
    Your blog about this issue was just a few days ago, and yet you denied today making any statements to the effect that the smaller microlenses in the GFX were leading to the prevalence of "oversharpened" GFX images that you have been seeing on line. The words were right there for all to see. If you have difficulty acknowledging in a candid way what you said just a few days ago (for reasons that completely escape me), how can you be so sure of what you said a few years ago?

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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by hcubell View Post
    Your blog about this issue was just a few days ago, and yet you denied today making any statements to the effect that the smaller microlenses in the GFX were leading to the prevalence of "oversharpened" GFX images that you have been seeing on line. The words were right there for all to see. If you have difficulty acknowledging in a candid way what you said just a few days ago (for reasons that completely escape me), how can you be so sure of what you said a few years ago?
    My blog post stands:

    https://blog.kasson.com/gfx-50s/on-m...and-gfx-50r-s/

    The combination of the small microlenses and overly aggressive capture sharpening is a bad one, and w=the amount of sharpening that is normal for large microlenses is too much for small ones. The small microlenses themselves are more subject to aliasing. I have become more negative about the small microlenses over time, especially with the GFX 100 in hand.

    But I have always acknowledged that the small microlenses have downsides. They are sharper, but the aliasing that comes along with that is a problem that seems more significant to me now that I can see a camera with roughly the same microlens size that has 1.4 times the resolution, so the same sharpness, but less aliasing.

    Jim

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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by hcubell View Post
    Your blog about this issue was just a few days ago, and yet you denied today making any statements to the effect that the smaller microlenses in the GFX were leading to the prevalence of "oversharpened" GFX images that you have been seeing on line.
    If you look carefully, you'll see that that's not exactly what I said:

    "I am not saying that the small microlenses are a problem because they encourage oversharpened images. I'm saying that they are a problem because of aliasing. That's a different thing entirely. The oversharpening occurs, I believe, because Lr and C1 did not adjust their default sharpening in order to take into account the small microlenses, leading to oversharpened images at the default sharpness settings. You can't blame that on the camera. "

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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by hcubell View Post
    Your blog about this issue was just a few days ago, and yet you denied today making any statements to the effect that the smaller microlenses in the GFX were leading to the prevalence of "oversharpened" GFX images that you have been seeing on line. The words were right there for all to see. If you have difficulty acknowledging in a candid way what you said just a few days ago (for reasons that completely escape me), how can you be so sure of what you said a few years ago?
    Howard,
    I'm willing to bet neither of you can be so sure of what you said a few years ago or what was said to you. My wife tells me I can't remember what I said 5 minutes ago. Please, for the rest of us, give it a rest. You both are great contributors here. This microlens issue ain't worth it.

    Dave
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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by P. Chong View Post
    I was wondering what you guys think of the thoughts expressed in the following article. I believe Lloyd Chambers also wrote something similar.


    https://blog.kasson.com/gfx-50s/on-m...and-gfx-50r-s/

    https://diglloyd.com/blog/2019/20190...ilmGFX50S.html

    If as Kasson suggested, the issue with the GFX50 is due to the microlenses on the sensor, is the same argument also applicable to the X1D sensor, since they are essentially the same. I haven't shot with GFX50, but I don't think I am seeing the crunchiness or oversharpening that is being discussed. Thoughts, anyone?
    I would simply test with a print. The information presented in the blog appear to be 100% monitor views, which don't reflect a normal viewing conditions. They also don't take a systemic view of the process to the final image, which can actually result in a perception of softness.

    Just as you can sharpen an image, you can also soften it. Is your perceived crunchiness from the sensor or the RAW processor? Look at the sharpening defaults and reduce them.
    Will

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    Re: GFX microlens discussion at Kasson

    Jim (Kasson),

    So if we switch off sharpening on C1 or LR or ACR during raw conversion, the oversharpening will go away, though we still have to deal with aliasing? Am I right that the workaround is to stop the lens down?

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    Re: GFX microlens discussion at Kasson

    I would not turn off all sharpening in C! or LR for a raw conversion, as you are still interpolating colors as with any raw conversion, if you capture R, you interpolate Green and Red, thus softness will be induced.

    I have over 10K of images from the 50s, I have yet to find anything wrong with them due to over sharpness. It's a personal preference, I realize but I think I understand the effects of over sharpening.

    If any raw conversion uses a special meta lens read from the GFX50s, it might be ACR/LR, as the images due tend to show a tendency to be over sharp, and you have to watch for haloing. I don't shoot subject matter that has ever shown aliasing in landscape subject matter with the 50s 3100 or 4150.

    What a lot of people miss is that that what you see on the web can be totally miss represented. Different monitor, different browser, and more important, what tool was used to upload the image. Many, myself included use flickr as one such tool, and for sure it adds sharpening to all my images. You can't turn it off, and if you present a well prepared image for print to flickr, it tends to get an over sharpened look. I personally don't have time to soften images just for web uses. Personally the vast majority of people viewing your work are on a phone or tablet neither of which can give a really good representation of your work, especially at 72 dpi, which is the web standard.

    It's no different for printing, as an image to printed on canvas requires a different level of sharpening vs an image on paper. And paper matters also, glossy vs matte and ink sets also. I don't think there is one set level of sharpening that works

    I still rely on 100% pixel view in CC or LR, and sharpen accordingly. I use the defaults for sharpening in C1 and less than the defaults in LR/ACR.

    I am more concerned about the color profile and noise characteristics of the raw conversion than if it's over sharpened, as I can easily correct for over sharpening, but correcting noise and or color is more time consuming.

    Sometimes I find that it's a bit easy to get off track

    The world is not blurred and most object have pretty amazing details, both man made and natural and producing an image that displays those details is my goal.

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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by P. Chong View Post
    Jim (Kasson),

    So if we switch off sharpening on C1 or LR or ACR during raw conversion, the oversharpening will go away, though we still have to deal with aliasing? Am I right that the workaround is to stop the lens down?
    Right on all counts, but I suggest just backing down on the sharpening in the raw converter, since turning it off entirely produces soft files. The microlenses on the GFX 50x are small, but they are not point samplers.

    Jim
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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by Shashin View Post
    I would simply test with a print. The information presented in the blog appear to be 100% monitor views, which don't reflect a normal viewing conditions. They also don't take a systemic view of the process to the final image, which can actually result in a perception of softness.
    I do test prints a lot. But they have a huge disadvantage for a blogger like myself: you can't show other people what they look like. In my informal tests, I do provide a recipe for the viewer to simulate looking at a print, but neither do I show the softening effect of a real printer using real paper, nor do I sharpen to compensate for that effect.

    Quote Originally Posted by Shashin View Post
    Just as you can sharpen an image, you can also soften it.
    This is true. You can sharpen an image, at a cost of SNR and spatial effects. You can soften an image and pick up SNR, but you may also have spatial effects. (Ask me to explain about the relationship of the space and frequency domains if that's not clear to you.) That in general argues for smaller microlenses.

    But here's the catch: If there's aliasing, you can't get rid of it by sharpening or softening. And small microlenses will create more aliasing.

    Quote Originally Posted by Shashin View Post
    Is your perceived crunchiness from the sensor or the RAW processor? Look at the sharpening defaults and reduce them.
    The effect is observable in the four raw planes, but only as a difference between the GFX 50x and GFX 100 files, not as "crunchiness", since you're looking at raw files with no sharpening at all.

    I do reduce the sharpening from the overaggressive Lr/ACR results. But it appears that not all people do that, from what I'm seeing on the web. And, as I said before, reducing the sharpening won't help if information is already aliased.

    Jim

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    Re: GFX microlens discussion at Kasson

    Interesting thread. I had not followed the microlens discussions since I am a recent owner of the 50s. I did notice on first use that the 32-64 seemed remarkably sharp, perhaps suspiciously so. When I found that Fuji had lens corrections baked into the RAW files I wondered if there was some file sharpening applied. This discussion motivated me to try a simple test today. Three heavily cropped images from the garden (actual pixels at 72ppi).
    In order the images are:
    1. 50s using a Pentax 67 55mm at f/8
    2. 645Z using the same 67 55mm
    3. 50s using the 32-64 mm @55mm and f/8.
    Both the images from the Fuji are slightly sharper (look at the center of the sunflower), and since software is not correcting for the 67 lens, my thought of baked-in sharpening can be dismissed, unless sharpening is blindly applied to all files regardless of lens used, which seems unlikely. Assuming the Fuji and Pentax are using the same basic sensor except for the microlenses, my results are consistent with Jim's suggestion. All images on a tripod, timer and zoomed in live view focus; default setting in ACR. I can't dismiss some focus error, although I had two exposures for each and don't see any evidence of such.

    Tom

    Addendum: The Pentax 67 55mm (last generation) appears slightly sharper than the Fuji zoom viewed at 400%; not very significant but good news for use with a shift adapter.
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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by JimKasson View Post
    I do test prints a lot. But they have a huge disadvantage for a blogger like myself: you can't show other people what they look like. In my informal tests, I do provide a recipe for the viewer to simulate looking at a print, but neither do I show the softening effect of a real printer using real paper, nor do I sharpen to compensate for that effect.



    This is true. You can sharpen an image, at a cost of SNR and spatial effects. You can soften an image and pick up SNR, but you may also have spatial effects. (Ask me to explain about the relationship of the space and frequency domains if that's not clear to you.) That in general argues for smaller microlenses.

    But here's the catch: If there's aliasing, you can't get rid of it by sharpening or softening. And small microlenses will create more aliasing.



    The effect is observable in the four raw planes, but only as a difference between the GFX 50x and GFX 100 files, not as "crunchiness", since you're looking at raw files with no sharpening at all.

    I do reduce the sharpening from the overaggressive Lr/ACR results. But it appears that not all people do that, from what I'm seeing on the web. And, as I said before, reducing the sharpening won't help if information is already aliased.

    Jim
    And given the pixel resolution of those sensors under normal shooting conditions with normal subjects, what are the chances that aliasing will be perceptible in a print? Every digital camera will alias. I am sure I have aliasing in my images somewhere, but I have yet to be able to identify it. Ultimately, the goal of cameras in the context of the photographers here is to produce a pleasing image. While the rigor of testing targets can be used to identify issues, the significance of those issues still need to be put into context of the process the systems will be used under, including to the final display.

    I think if a photographer is concerned about what you have found, they should be systematic and produce prints to see the systemic effect of the microlenses. The print is the best way to put some of these effects into context, especially with such high MP sensors. That was simply my recommendation.
    Will

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    Re: GFX microlens discussion at Kasson

    Interesting discussion.
    Regarding the image sizing for web displaying I just want to add a point: let's not forget that many new device displays don't feature 72DPI anymore, most of them are now above 200DPI.
    I personally experience a huge difference in perceived sharpness when seeing the same image on my old full-hd monitor and on my MBP retina display.
    Another consequence is that now I don't know what should be the right size of an image for web displaying, the old sizes like 800-1024px long side seem now too soft or too small (depending on the configured scaling factor) on retina displays.
    Marco Ristuccia
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    A bit of perspective...

    Hi,

    Aliasing was always a part of medium format. Please do remember that essentially all MFD cameras lack OLP (Optical Low Pass) filters, with the exception of the early Kodak backs and the Mamiya ZD that offered an OLP filter as an option.

    Combining a good lens with relatively large pixels is a sure recipe for aliasing. But, aliasing yields fake detail instead of true detail. That is the reason it is called aliasing. It converts high frequency detail that the lens transmits into low frequency aliases.

    The reason that photographers don't object to aliasing is that it is not very obvious, unless it shows up as color moir.

    Now, for some reason I don't really understand, Fuji claimed to have reduced the pixel aperture on the GFX 50S/R. Any point of the image is smeared out over the pixel aperture, so a small pixel aperture increases contrast at the pixel level, but it will also produce fake detail. So, Fuji essentially choose pixel level contrast over correct reproduction.

    Now, we don't know if other vendors have used the same trick. But, wait a moment...

    Reducing the pixel aperture means that the pixel collects less light, doesn't it.

    Now, let's look at the DPReview test images for the GFX 50/S, GFX 100, Hasselblad X1D and the Phase One XF/IQ 3100MP combo:

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    We can see that both 50 MP sensors show a large amount of aliasing, while the 100 MP backs are almost aliasing free. Note also that the X1D shows more aliasing than the GFX. That would indicate that either the 90/3.2 lens on the X1D is much sharper or that both use similar pixel aperture.

    Reducing pixel aperture significantly would reduce quantum efficiency, leading to longer exposure, but both the X1D and the GFX 50/S use the same exposure f/8 and 1/20s.

    Comparing raw exposures for the GFX50S (DSC3041.RAF) and Hasselblad X1D (B0000401.3FR) we can see that there is not a huge difference between G channels:
    Click image for larger version. 

Name:	Info2.JPG 
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    So both are about 1.4EV under saturation, with presumed saturation at +3EV.

    SNR is essentially the square root of the photoons captured.

    GFX 50S has SNR = 6821 / 56.9 -> 110
    X1D has SNR = 28375 / 236 -> 120

    So SNR is pretty close and it seems that the X1D got slightly more exposure (relative saturation). But the differences do not indicate a huge difference in pixel aperture size.

    The great unknown here is of course if DPReview uses a variable light source. Their description of the protocols used could be more comprehensive.

    My take is really:

    • MFD users like aliasing, as it gives an impression of sharpness.
    • Fuji with the GFX is obliging by using relatively small pixel apertures.
    • The Hasselblad X1D gives similar amount of aliasing as the GFX 50.


    Jim's investigation shows that the GFX 50/S has higher MTF at similar cy/mm than the GFX 100. So the GFX 100 obviously has smaller physical pixel aperture than the GFX 50/S. So the GFX 100 has no more acutance than the GFX 50/S, but resolves finer detail.

    I always said that both the GFX 50/S and the X1D cried for a higher resolution sensor. Jim's findings show why!

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    Re: A bit of perspective...

    Quote Originally Posted by ErikKaffehr View Post
    Hi,

    We can see that both 50 MP sensors show a large amount of aliasing, while the 100 MP backs are almost aliasing free. Note also that the X1D shows more aliasing than the GFX. That would indicate that either the 90/3.2 lens on the X1D is much sharper or that both use similar pixel aperture.
    Or that the GFX image is misfocused.
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    Re: A bit of perspective...

    Quote Originally Posted by JimKasson View Post
    Or that the GFX image is misfocused.
    Good point!

    Anyway, I think that both systems seem to be able to produce excessive aliasing.

    Just to say, I would think that the GFX 50R image has slightly less accurate focus compared to the GFX 50S image.

    Best regards
    Erik
    Last edited by ErikKaffehr; 4 Weeks Ago at 10:08.

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    Aliasing and printing

    Quote Originally Posted by Shashin View Post
    And given the pixel resolution of those sensors under normal shooting conditions with normal subjects, what are the chances that aliasing will be perceptible in a print? Every digital camera will alias. I am sure I have aliasing in my images somewhere, but I have yet to be able to identify it. Ultimately, the goal of cameras in the context of the photographers here is to produce a pleasing image. While the rigor of testing targets can be used to identify issues, the significance of those issues still need to be put into context of the process the systems will be used under, including to the final display.

    I think if a photographer is concerned about what you have found, they should be systematic and produce prints to see the systemic effect of the microlenses. The print is the best way to put some of these effects into context, especially with such high MP sensors. That was simply my recommendation.
    I took a crack at this:

    https://blog.kasson.com/gfx-50s/visi...ing-in-prints/

    The question of the desirability of aliasing is a separate issue, but it was clear in the era of 16 and 22 MP MF cameras that some people not only tolerated, but enjoyed, aliasing.

    Jim
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    Re: GFX microlens discussion at Kasson

    I wasn't sure how seriously to treat this issue until I made a picture today that shows the problem vividly. I'm using a Fuji GFX 50R. The lens is a Rodenstock Rodagon-WA 60mm f/4.

    The RAW developer used on the RAF plays an interesting role. I tried three RAW developers: Lightroom, Iridient X Transformer and Capture 1 Express for Fuji (exporting as a TIFF that I brought into LR).
    * Lightroom showed the least aliasing but the most "mazing".
    * IXT and C1 were about the same for mazing and aliasing. Oddly, the aliasing appeared in bands in C1 and IXT, but not in LR.

    I then had a look at the JPEG that was created alongside the RAF: no aliasing is evident, and the mazing is minimal. The same is true when you develop the RAF in camera and save it as a TIFF. That's not an ideal solution, but in the cases where the problem is severe, it's a decent work-around.

    These are crops to what would be roughly 300%. In order from left to right, Top row: Lightroom, IXT, C1; Bottom row: in-camera JPEG, in-camera TIFF.

    Now I'm wondering what it is that the camera is doing with the RAF that these RAW developers are not doing....

    Click on this link to see the different versions (goes to my Google drive): https://drive.google.com/open?id=1WB...WPu21MBN1hlO_h

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    Re: GFX microlens discussion at Kasson

    I find interesting how much difference the RAW converter makes. On the same Fuji GFX 50R RAF file, I get dramatically different results using Lightroom 8, Capture 1 Express for Fuji, Iridient X Transformer, and the camera itself.

    In an area showing the effects of aliasing in an image I tested yesterday, Lightroom left behind the strongest "mazing" pattern, but the fewest large-scale colour aretfacts. Capture 1 and IXT had less mazing but strong colour artefacts in the form of moire banding. The in-camera JPEG processor left behind a tiny bit of mazing and no colour artefacts. In-camera RAW processing produces a TIFF that (not surprisingly) matches the JPEG relative to colour patterns and mazing.

    A pleasant surprise was the new Enhance Details function in Lightroom 8. It did a very good job of cleaning up the colour and mazing artefacts. It's definitely not perfect (can't make a silk purse out of a sow's ear), but it's a vast improvement. Calling it "Enhance Details" is a bit of a misnomer in my opinion. It leaves the rest of the image alone and focuses just on problems areas -- very much like the tools for tidying up chromatic aberrations.
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    Re: GFX microlens discussion at Kasson

    Quote Originally Posted by rdeloe View Post
    I find interesting how much difference the RAW converter makes. On the same Fuji GFX 50R RAF file, I get dramatically different results using Lightroom 8, Capture 1 Express for Fuji, Iridient X Transformer, and the camera itself.

    In an area showing the effects of aliasing in an image I tested yesterday, Lightroom left behind the strongest "mazing" pattern, but the fewest large-scale colour aretfacts. Capture 1 and IXT had less mazing but strong colour artefacts in the form of moire banding. The in-camera JPEG processor left behind a tiny bit of mazing and no colour artefacts. In-camera RAW processing produces a TIFF that (not surprisingly) matches the JPEG relative to colour patterns and mazing.

    A pleasant surprise was the new Enhance Details function in Lightroom 8. It did a very good job of cleaning up the colour and mazing artefacts. It's definitely not perfect (can't make a silk purse out of a sow's ear), but it's a vast improvement. Calling it "Enhance Details" is a bit of a misnomer in my opinion. It leaves the rest of the image alone and focuses just on problems areas -- very much like the tools for tidying up chromatic aberrations.
    I cant argue with any of that.

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