It is impossible to correct for field curvature in post.
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A Q2 shot with Massive DOF
- Thread starter Greg7579
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Greg7579
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Well then, I can assure you that this is not a problem with that great lens and that world-class amazing little FF 50 MP camera. The image fidelity on the Q2 is absolutely amazing. It is a nice 50MP FF sensor combined with one of the very best prime lenses on Planet Earth. The Q2 is incredible. Why do you think so many discerning GFX shooters have one? It's not for the Red Dot. Well.... Maybe a little.I'm unfamiliar with the lens on the Q2, but the issue would be more likely distortion than field curvature. When the digital correction is applied to distortion it wreaks havoc on the image quality, most notably in the corners.Is field curvature the reason for the softness in the bottom corners. For a lens that’s supposed to be considered special I’m shocked at how bad it is stopped down to f7.1. I would expect that wide open but not at that aperture.I am not a programmer or computer scientist and I can't write code. But I am a PC hobbyist and have been since the dawn of the PC age (build my own rigs). I have never used Apple stuff but think they are amazing. Anyway, I am not technical about windows discussions so I have to be careful, but I have followed the heated discussions about windows being way behind Mac on scaling from the dawn of the 4K age. But they fixed that and Windows is as good as the Apple OS now when it comes to scaling. But a lot of it is still software and website specific. 8K is going to be interesting. Can't wait.
Adobe jumped on this 4k scaling thing early with Microsoft because they had pro content developers and photographers using LR and PS with PCs and servers and there were these new 4K monitors. Adobe nailed it early and pretty well. So in Windows when you ask for 1:1 with LR or PS, that is what you get. You don't get 1:2.5. Maybe you do when you open a jpeg out of DPR at what they call 100% view. If so, DPR needs to fix that. But anyway, Windows will suggest that you set to 150% for almost any 32 inch 4K IPS pro monitor in order to change the size of text, play well with most apps and to assist with the proper scaling overall. Anyway, I'm not technical on that aspect so thanks for the info. I could always be wrong about some of that explanation.
Yes I did and I didn't like what I saw, but it was better than viewing it straight up on DPR. But, 100% in PS is really true pixel res. Same for LR. They talk about that all the time on the LR and Adobe boards. Adobe does that well. By the way, I'm not bashing DPR for this but this is the leading photo equipment website and this is the MF Board where we talk the nuances, compare shots and post some of the highest res images in the world. They could do better.
I export all jpegs to DPR as full-size jpegs at 85 to 88% quality and have for a long time. Jim and I have had this discussion many times and he guided me through that minefield three years ago. I was asking whether to downsize the jpeg export from LR or just make it lower quality in order to get the jpeg at low enough MP to post on DPR. 45 MB files will usually post and 48 will not. I try to stay around 30 MB by lowering the quality setting. Some have said you can drop to 80% in LR exports and it is indiscernible and you get much smaller jpegs. That algorithm is something isn't it? The limit on DPR is around 48. You try 50 and your post locks and you have to crash out of it. They should have a warning....
Yes, especially DPR. I think they need to lighten up and give up some of that massive server space or borrow some from their owner and master - Godzilla. That is not an insult. Godzilla let King Kong live in the last movie. He had him down and out....
I know all of the equivalencies of course and am aware of the challenges of posting side by side comparison shots with different systems, sensor sizes and lenses. The variables are endless. You know the list....
I have not noticed FC on my Q2 (maybe because it is so well corrected when I pop open the DNG file in LR). Can I turn that off in LR and see it without the corrections applied? I would like to go peep one uncorrected. So FC with that awesome little mm prime is really "massive: and distortion is massive? I thought that 28 on the Q2 was one of the top 3 lenses in the World. That's what everyone tells me. That lens is that bad? I need to go back and read the Leica Q2 reviews and see what they great reviewers said about that. I honestly don't remember and I read them all.
Would love to see it. Tell me how to peep a Leica Q2 DNG uncorrected.
Wow! I believe you but I did not know that. How can that never be mentioned on the Leica Board? That said, that board is probably the absolute least technical of all the boards, which is pretty amazing because you would think it would be otherwise.
Amazing. Smaller than FF. The Leica Q2 is smaller than FF? Would someone elsew like to comment on that? How much smaller?
Yes, that I am very aware of and has been talked about a lot since we GFX shooters are shooting at 4:3. I love 4:3. That has been noted by Erik and Jim before as being one of the nuances that is "tricking" me into believing the difference between GFX and FF DOF is way more than one stop. But I don't harp on that number anymore and don't care so much. I just say I notice a big difference. Sometimes bigger than big. Like on that shot.
That was a fine post Sir. You should start a thread with this information on the Leica Board. The Q2 shooters there would appreciate it. And a Hell of a lot of them are GFX shooters too because the Q2 and GFX go together like Michael Jackson's hand in a sequined glove in 1985.
The Q2 is my all-time absolute most favorite camera. Now I could never just use it alone for a long period of time. Maybe for a day, or a hike. The beautiful Q2.... When I have it around my neck, which is a lot, it makes me happy. When I hold it in my hand, it makes me happy. When I look at it, it makes me happy. Sometimes I pet it and moan softly while on the airplane after gently taking it out of the shoulder bag piled on top of the GFX 100 body sand EVF.... I say to it, Darling - I can't wait to get you alone on Sicily...Ohhhh My Love ... the things we are going to do together....Those little emojis are me smooching with my sexy little Q2. Her name is Ansell, and she has some bumps and bruises from banging up against my GFX 100 for two years.
My problem is my GFX 100 body and my Q2 body are all banged up because they are constantly bashing into one another around my neck, in my bag, and in the back seat and floorboards of my truck. They sound like two bowling balls bumping up against each other as I drive or stroll down the road or walk through parks and alleyways.. Luckily, most of the scratches and dents on my GFX 100 are on the RRS L Plate and on the Q2 the scratches and dents are mostly on that awesome twist-on metal hood that is permanently on the 28mm lens that has so much horrible distortion and FC.
On another note of interest to the Board, I just sent my Q2 to Germany because they are going to help me with a little problem I have. I also just mailed my GFX 100 to Steve in NJ because I have a couple of little issues that they are going to help me out with. These are all little bumps in the road, but I bet it takes me two months to get that Q2 back from Germany. The 100? 5 days I bet. Those guys are great.
While doing a couple of minor repairs (including replacing my totally no-friction tilt adapter), they are also going to check out my GFX 100 as it has been over some rocky road lately. I even asked them to check for a tilted sensor, even though I know mine is not tilted because I pixel-peep every shot and I know what right looks like.
But here's the thing.... I also know what wrong looks like.
That was a good post Man. Thanks.
Jared Willson
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Is field curvature the reason for soft corners? No. Field curvature doesn’t make lenses softer—it just changes the plane of focus. Bottom edges of images tend to be closer to the camera, so field curvature (generally closer as you move away from the center) actually helps the lower edge and corners. Field curvature would hurt sharpness at the top of most images, but that is often “sky” that is devoid of detail so one doesn’t notice.
Lack of sharpness in the corners is a combination of ordinary optical defects and, in particular, distortion correction.
When you fix distortion in software, you obviously need to make bigger corrections in the corners than anywhere else. Effectively, you might smear the data from one pixel across the area that should be covered by two. This can degrade sharpness somewhat. To see how much you would have to compare an uncorrected and a corrected image as it will vary from one lens design to the next. The more the distortion correction, the greater the loss in detail. However, it’s usually pretty minor with most lenses, and it only is noticeable in the extremities. Lightroom and Adobe won’t let you disable the distortion correction in the Q. Some other packages will.
The way Leica chose to design the Q was as a combined optical/software system. They were able to achieve a fast lens with insane resolution overall in a compact size with OIS by NOT fully correcting for distortion optically. Instead, software takes care of that particular issue. Saves a lot of bulk while maintaining excellent detail throughout most of the image.
Is the Q less than full frame? Of course not. It’s a full frame camera. Heck, most cameras have regions of the chip that are not used—just for calibration as they are optically black. That’s why pixel counts in the final image sometimes don’t match spec sheets—at least it’s one reason why. It’s still a full frame camera. Does it throw away some data in the corners? Absolutely. Distortion correction necessarily does that. All profiles with distortion correction throw away some corner data. The Q has more distortion than most so loses more corner data than most. You lose some field of view in the corners as well as some resolution due to the “stretching” of data. It’s a good compromise, though obviously not ideal for all pictures.
Lack of sharpness in the corners is a combination of ordinary optical defects and, in particular, distortion correction.
When you fix distortion in software, you obviously need to make bigger corrections in the corners than anywhere else. Effectively, you might smear the data from one pixel across the area that should be covered by two. This can degrade sharpness somewhat. To see how much you would have to compare an uncorrected and a corrected image as it will vary from one lens design to the next. The more the distortion correction, the greater the loss in detail. However, it’s usually pretty minor with most lenses, and it only is noticeable in the extremities. Lightroom and Adobe won’t let you disable the distortion correction in the Q. Some other packages will.
The way Leica chose to design the Q was as a combined optical/software system. They were able to achieve a fast lens with insane resolution overall in a compact size with OIS by NOT fully correcting for distortion optically. Instead, software takes care of that particular issue. Saves a lot of bulk while maintaining excellent detail throughout most of the image.
Is the Q less than full frame? Of course not. It’s a full frame camera. Heck, most cameras have regions of the chip that are not used—just for calibration as they are optically black. That’s why pixel counts in the final image sometimes don’t match spec sheets—at least it’s one reason why. It’s still a full frame camera. Does it throw away some data in the corners? Absolutely. Distortion correction necessarily does that. All profiles with distortion correction throw away some corner data. The Q has more distortion than most so loses more corner data than most. You lose some field of view in the corners as well as some resolution due to the “stretching” of data. It’s a good compromise, though obviously not ideal for all pictures.
This has been explained to you several times. You're not getting it. I'll try again. DPR prohibits repetitive links to commercial sites, identifying that as spam. The two sites you mention are commercial sites. They sell ads and monetize eyeballs. A link here and there to either of those seems to be acceptable. Many such links would be spam.
There are no ads on my blog. I don't make any money with my blog. It exists as a service to photographers the world over. It is not a competitor to DPR. There are no general fora.
That's the difference. Got it now?
Jared Willson
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Greg7579
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I know. So do yopu think the 28 has a lot of FC? I don't think it does. Do you? I could be wrong.
Greg7579
Forum Pro
So are you guys telling me that or the guy who said it?
--
Greg Johnson, San Antonio, Texas
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DPR specifically allows linking to your portfolio, but cautions you that overdoing it could be considered spam. Flickr is a commercial site, so that moves it towards a gray area. I think that the number of links would be dispositive.
If you want to control how your images are presented to your audience, I suggest setting up your own website, putting your pictures there, and not using any ads.
Jim
Erik Kaffehr
Veteran Member
I used to have a blog, but got tired of the content management tool I was using.
Writing a good article takes a lot of time.
- Careful analysis
- Doing experiment
- Evaluate the results
- Writing an article
Also, almost certainly, the forum discussion will be derailed by some guy with great self esteem but little knowledge.
Elements of image quality...
This is intended to small summary of the aspects going into image quality. The discussion ignores color and things unmeasurable. The major factors are: Photons - that is the light forming the image Lens OTF - that is the information that lens transfers to the sensor Diffraction - that is the...
Now check who has commented on that...
Publishing under your own control is much more rewarding.
Best regards
Erik
Who said it? Where? When?
Hamiltionian
Senior Member
I didn't see evidence of significant FC in the image you posted, but that is my only point of reference. The link to reddit above did demonstrate some distortion that is corrected in camera, but not an egregious level, especially for the world of fixed lens cameras.
Hamiltionian
Senior Member
Yeah, from the links further down in the thread it is clear that the level of distortion isn't bad, and I absolutely believe on the image quality you can get out of that little camera. I shoot a Fuji X100F and its a great little camera, but I wouldn't mind if it was a Q2 instead.Well then, I can assure you that this is not a problem with that great lens and that world-class amazing little FF 50 MP camera. The image fidelity on the Q2 is absolutely amazing. It is a nice 50MP FF sensor combined with one of the very best prime lenses on Planet Earth. The Q2 is incredible. Why do you think so many discerning GFX shooters have one? It's not for the Red Dot. Well.... Maybe a little.
Then why did you ask if you could turn off correction in Lr?
Never tested it, so I have no opinion.
I'm commenting on what you said. To my knowledge, no one ever said in this thread that there is software correction for FC.
Hamiltionian
Senior Member
I'd go a step further and suggest that Jim isn't overly concerned with the number of views on his site either.
highdesertmesa
Senior Member
Yes, the Q2 sensor is a full frame sensor, but the lens is projecting about a 26mm image onto that sensor and the DNG is flagged for C1/LR to crop the image down to just below 28mm. So it's true the Q2 is full frame, but it's also true the final images are not. This is much more aggressive software correction and cropping than we are used to seeing. The Q2 images are cropped on all sides, but most heavily on the long sides due to the 3:2 image ratio.
https://www.l-camera-forum.com/topic/307158-q2-24mm-51m-pixels/?do=findComment&comment=3927156
If you want to see what's going on with Q2 corrections, open one in Capture One and turn off all the lens corrections. It's quite sobering. But the end result is still very good because the lens and sensor were designed for each other. The IQ from this fixed-lens setup is so good, they can crop and software correct and still have a very nice image. The only negative noticeable impact to IQ will be in the corners, where they are a little soft at infinity at any aperture. The corners at infinity on the Q are also very susceptible to filter quality. The Leica brand UVa and B+W Nano Clear both make it worse. Zeiss T* UV filters seem to have no impact on IQ.
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I have no clout with DPR. And you are mischaracterizing the effects of their compression. If you don't like their compression, link to an ad-free site with your images on it.I have a better idea. Use your clout to get DPR to allow us to post some MF shots that don't look like my wife's iPhone shots blown up on my studio monitor.Post the raw on Dropbox. There’s single pixel detail in the center of that crop.Nope. That garbage you posted from the DPR crop is nothing remotely like I see on my monitor with the raw or my jpeg at 1:1.Greg, you haven't responded to this post , though you've responded to others since. I think this whole thread is overblown. I downloaded the JPEG of your original post from DPR. I looked at it with extreme pixel-peeping settings, and posted the results in the link above.
There is pixel-level detail there, but not in the foreground.
Sure there's compression going on, but it's not enough to invalidate judging the sharpness of your image, and indeed it's enough to show that there is about the expected amount of DOF-caused degradation of image sharpness.
And here's a tight crop of what I see in my browser window at 100% on a 4K monitor;
This is a PNG file so there's less compression.
Let's flatten that mountain and call it a molehill.
Not even close. And after shooting probably 50,000 GFX shots, I can tell you for damn sure that no GFX shot on a scene like that will have anywhere near that DOF. Not even close. Like I said, it slaps you in the face it is so obvious.
Go back and look at your old images; are they similarly afflicted?
--
the last word the last word - Photography meets digital computer technology. Photography wins -- most of the time.
Photography meets digital computer technology. Photography wins -- most of the time.
blog.kasson.com
Kodalith.Nope. That garbage you posted from the DPR crop is nothing remotely like I see on my monitor with the raw or my jpeg at 1:1.Greg, you haven't responded to this post , though you've responded to others since. I think this whole thread is overblown. I downloaded the JPEG of your original post from DPR. I looked at it with extreme pixel-peeping settings, and posted the results in the link above.
There is pixel-level detail there, but not in the foreground.
Sure there's compression going on, but it's not enough to invalidate judging the sharpness of your image, and indeed it's enough to show that there is about the expected amount of DOF-caused degradation of image sharpness.
And here's a tight crop of what I see in my browser window at 100% on a 4K monitor;
This is a PNG file so there's less compression.
Let's flatten that mountain and call it a molehill.
Not even close. And after shooting probably 50,000 GFX shots, I can tell you for damn sure that no GFX shot on a scene like that will have anywhere near that DOF. Not even close. Like I said, it slaps you in the face it is so obvious.
the last word the last word - Photography meets digital computer technology. Photography wins -- most of the time.
Photography meets digital computer technology. Photography wins -- most of the time.
blog.kasson.com
AudiiDudii
Leading Member
Greg:
As I was eating my lunch, I got to thinking about your predicament and decided to share a few of my thoughts with you...
Nearly two decades ago, when I first started posting .jpg versions of my photos online, I quickly realized that a lot of image quality was left behind or disappeared if I didn't take the time to optimize their file size / appearance before I uploaded them.
Frankly, considering how particular you are about the appearance / quality of your photos -- and rightly so, I might add! -- I'm a bit surprised to learn that you haven't been doing the same thing yourself.
Personally, posting a 40+MB .jpg to a forum strikes me as being completely over the top. Linking to such a file so anyone who wants to see the full-res version is great, but actually posting it to a forum at that size, leaving it up to the forum host to deal with it, and then assuming / expecting they'll treat it kindly in the process is -- IMO, anyway -- completely misguided and hopelessly unrealistic.
So far as I'm concerned, the only person who ever gets to process and/or print my photos is ME!
Given the state of today's technology, both processes require considerable compromises to be made along the way and the only person I trust to make judgment calls in my favor is -- you guessed it -- ME!
It's for this reason that after I process my photos as 16-bit .tifs to my satisfaction, I then go on to create the relatively tiny .jpg versions that I post online or email to friends.
This puts me in full control from the time photons arrive at my camera's sensor until the final, finished file is uploaded from my computer to another computer, at which point whatever happens to it is out of my hands.
Similar to long-distance target shooting, once the bullet leaves the barrel, your job as the shooter is finished, the ultimate success or failure of its mission is out of your hands, and all you can do is hope for the best.
Mind you, preparing a .jpg for online use isn't easy, at least initially. But once you figure out how to lead the target, so to speak, the process can be made quite routine. In fact, I created an action in Photoshop that performs all the necessary tweaks and adjustments required to do so with my photos and it launches with just a single click of my mouse!
You can huff and puff all you want about how you think DPR should accommodate the massive .jpgs you want to post to their forums, but as a practical matter, it's a lot easier and you'll achieve much better results if you expend less effort and time -- remember, a single mouse-click is all that's needed after everything's setup! -- and accommodate DPR instead. You know, go with the flow and all that...
I'm just sayin', that's all... 8^)
As I was eating my lunch, I got to thinking about your predicament and decided to share a few of my thoughts with you...
Nearly two decades ago, when I first started posting .jpg versions of my photos online, I quickly realized that a lot of image quality was left behind or disappeared if I didn't take the time to optimize their file size / appearance before I uploaded them.
Frankly, considering how particular you are about the appearance / quality of your photos -- and rightly so, I might add! -- I'm a bit surprised to learn that you haven't been doing the same thing yourself.
Personally, posting a 40+MB .jpg to a forum strikes me as being completely over the top. Linking to such a file so anyone who wants to see the full-res version is great, but actually posting it to a forum at that size, leaving it up to the forum host to deal with it, and then assuming / expecting they'll treat it kindly in the process is -- IMO, anyway -- completely misguided and hopelessly unrealistic.
So far as I'm concerned, the only person who ever gets to process and/or print my photos is ME!
Given the state of today's technology, both processes require considerable compromises to be made along the way and the only person I trust to make judgment calls in my favor is -- you guessed it -- ME!
It's for this reason that after I process my photos as 16-bit .tifs to my satisfaction, I then go on to create the relatively tiny .jpg versions that I post online or email to friends.
This puts me in full control from the time photons arrive at my camera's sensor until the final, finished file is uploaded from my computer to another computer, at which point whatever happens to it is out of my hands.
Similar to long-distance target shooting, once the bullet leaves the barrel, your job as the shooter is finished, the ultimate success or failure of its mission is out of your hands, and all you can do is hope for the best.
Mind you, preparing a .jpg for online use isn't easy, at least initially. But once you figure out how to lead the target, so to speak, the process can be made quite routine. In fact, I created an action in Photoshop that performs all the necessary tweaks and adjustments required to do so with my photos and it launches with just a single click of my mouse!
You can huff and puff all you want about how you think DPR should accommodate the massive .jpgs you want to post to their forums, but as a practical matter, it's a lot easier and you'll achieve much better results if you expend less effort and time -- remember, a single mouse-click is all that's needed after everything's setup! -- and accommodate DPR instead. You know, go with the flow and all that...
I'm just sayin', that's all... 8^)
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