Clinical vs. Character?

[MrHollywood]

But what I'm pushing back against is the idea that the very best lenses, which tend to give the best and most accurate transmission of light, are somehow "cold or clinical."

That's just hogwash.

Robert, I am in full agreement with you. Recently, in this forum, someone was criticizing the Niikkor Z MC 105 f/2.8 VR S for being too sharp for portraits. I disagree. There are lots of ways to reduce sharpness in a photograph, starting with physical diffusion filters or during processing.

Yikes! Who said that? The 105 MC is excellent for portraits. And you can easily adjust the sharpness and other qualities in post. OOF transitions are very good as well.

Most recently here:

https://www.dpreview.com/forums/thread/4803980#forum-post-68268711

In other threads, there have been repeat occurrences of the (IMO untrue) idea that the 105/2.8 MC is bad for portraiture ("flat rendering") because of its flat focus field.

My main quibble with it (versus the Plena) is the cat's eye bokeh in the periphery, which can be a bit distracting when shooting against certain backgrounds. Other than that, I think it is a great lens.

All nonsense. The flatter field is a great tool for portrait work.

BTW, The Plena has fairly flat field focus, and it's basically a dedicated portrait beast, so there's a good indicator of what people don't know about glass.

The only real weakness of the 105 MC is that it's a tad slow at 2.8, though still very capable of nice bokeh and isolation.

Robert

 

[BasilG]

But what I'm pushing back against is the idea that the very best lenses, which tend to give the best and most accurate transmission of light, are somehow "cold or clinical."

That's just hogwash.

Robert, I am in full agreement with you. Recently, in this forum, someone was criticizing the Niikkor Z MC 105 f/2.8 VR S for being too sharp for portraits. I disagree. There are lots of ways to reduce sharpness in a photograph, starting with physical diffusion filters or during processing.

Yikes! Who said that? The 105 MC is excellent for portraits. And you can easily adjust the sharpness and other qualities in post. OOF transitions are very good as well.

Most recently here:

https://www.dpreview.com/forums/thread/4803980#forum-post-68268711

In other threads, there have been repeat occurrences of the (IMO untrue) idea that the 105/2.8 MC is bad for portraiture ("flat rendering") because of its flat focus field.

My main quibble with it (versus the Plena) is the cat's eye bokeh in the periphery, which can be a bit distracting when shooting against certain backgrounds. Other than that, I think it is a great lens.

All nonsense. The flatter field is a great tool for portrait work.

BTW, The Plena has fairly flat field focus, and it's basically a dedicated portrait beast, so there's a good indicator of what people don't know about glass.

Extremely flat, in fact (I checked). That was my exact response to this claim.

 

[Hal Wilson]

Okay, I'm gonna state unequivocally that the idea that a lens like an 85 1.2s or Plena or Noct .98 is "cold and clinical" is a concept designed to protect clearly inferior optics.

A "clinical" or "cold and clinical" lens means you have a lens that is devoid of distortion, softness or lack of contrast. It intrudes less on the passage of light than a so-called "lens with character." The character of an image should start clean and unencumbered by weaker optical design. The character of the image should be the choice of the artist both at the scene in post. Less "character" from a lens means more latitude to manipulate the image to the satisfaction of the artist.

For once, I agree with you. The whole 'character' thing is just subjective waffle imo. I wouldn't even bother with subjective terms such as 'cold and clinical'. Just say 'accurate'. Or you could use the term 'high fidelity'. And speaking of Hi-fi; people use the same kind of subjective language there too; you'll hear people endlessly extolling the virtues of vinyl, whilst what they're actually talking about are inadequacies of the turntable system to faithfully reproduce sounds as recorded. Nothing beats a modern digital reproduction for accuracy and dynamic range. But that doesn't mean people aren't allowed to like the extra sounds the turntable system introduced to the music, or the 'swirly bokeh' or other lens flaws. That's fine. But the fact is that liking such doesn't make the music or photos 'better', it just makes them different. And as the reception of art is always entirely subjective, so vinyl or lenses with flaws will always remain within that realm of subjectivity.


The next part of it lies with human insecurity; people don't want to admit or talk about their equipment being in any way 'flawed', lest it reflects negatively on their character and abilities as a person, so they introduce more positive spin on things, hence the 'character' of lenses, or the 'warm, rich sound' of vinyl. Etc. Which again is fine, but people would do well to realise, acknowledge and understand this. Subjectivity is great; it's what allows art in the first place, but leave out the pretentiousness and BS. Be honest; just say 'I like the effect this crap old lens produces', or 'I like the scratchiness of vinyl cos it reminds me of when I was a kid hearing my parents LPs', or whatever. Take time to understand your own emotional and even subconscious response to things. Because those are what are going to make you a better artist, not parroting pretentious waffle you read online or hard in a YT video.

 

[chuckhatcher]

…

The next part of it lies with human insecurity; people don't want to admit or talk about their equipment being in any way 'flawed', lest it reflects negatively on their character and abilities as a person, so they introduce more positive spin on things, hence the 'character' of lenses, or the 'warm, rich sound' of vinyl. Etc. Which again is fine, but people would do well to realise, acknowledge and understand this. Subjectivity is great; it's what allows art in the first place, but leave out the pretentiousness and BS. Be honest; just say 'I like the effect this crap old lens produces', or 'I like the scratchiness of vinyl cos it reminds me of when I was a kid hearing my parents LPs', or whatever. Take time to understand your own emotional and even subconscious response to things. Because those are what are going to make you a better artist, not parroting pretentious waffle you read online or hard in a YT video.

This insecurity works both ways, when the owner of a newer, more perfect lens, like the Plena, is compelled to relegate other equipment to the dustbin of history because it doesn’t measure up to a narrow definition of perfection.

I’m not knocking the Plena - I own one myself. It truly is an improvement over previous 135mm lenses - in some ways. But it’s most often not my chosen lens in actual use, for multiple reasons that have nothing to do with accuracy, sharpness, or relative freedom from aberration.

 

[Hal Wilson]

…

The next part of it lies with human insecurity; people don't want to admit or talk about their equipment being in any way 'flawed', lest it reflects negatively on their character and abilities as a person, so they introduce more positive spin on things, hence the 'character' of lenses, or the 'warm, rich sound' of vinyl. Etc. Which again is fine, but people would do well to realise, acknowledge and understand this. Subjectivity is great; it's what allows art in the first place, but leave out the pretentiousness and BS. Be honest; just say 'I like the effect this crap old lens produces', or 'I like the scratchiness of vinyl cos it reminds me of when I was a kid hearing my parents LPs', or whatever. Take time to understand your own emotional and even subconscious response to things. Because those are what are going to make you a better artist, not parroting pretentious waffle you read online or hard in a YT video.

This insecurity works both ways, when the owner of a newer, more perfect lens, like the Plena, is compelled to relegate other equipment to the dustbin of history because it doesn’t measure up to a narrow definition of perfection.

Well no, because that's not really happening here, is it? Just the statement of the fact that certain lenses are optically superior. And that the term 'character' is used to cover up flaws. It's much more of an Emperor's New Clothes scenario, with some calling out the Imperial nudity. Nobody is calling for those flawed lenses to be 'consigned to the dustbin of history'. That hasn't happened.

I’m not knocking the Plena - I own one myself. It truly is an improvement over previous 135mm lenses - in some ways. But it’s most often not my chosen lens in actual use, for multiple reasons that have nothing to do with accuracy, sharpness, or relative freedom from aberration.

But you have to accept that is purely down to subjective choices, nothing else. It's because you have a personal preference. Someone else might make a different choice. But nobody could argue that the superior lens isn't superior, as facts trump subjectivity.

 

[F786]

This "something" may, or may not be related to a few things, including sharpness at the focus plane, sharpness in front of or behind the focus plane, transition to OOF, and even within the construct of resolution at the plane of focus, the weighting/balance of contrast versus various spatial frequencies from coarse to medium to fine to very fine, dependent on what the scene offers. It gets really interesting when you add in that I'm beginning to feel that not everyone is sensitive to the same things in this regard - some tend to see it quickly, some never will, some in one use case/scene, some not in the other, and use case plays a part too. Which makes the matrix of possible combinations really complex, and not something you can easily measure with a letter grade or a score on a site.

Well said.

Factor in all the numerous and changing variables that go into making an image and then add the complication/beauty of how a human eye (lens) then receives the image, transmits it to the retina (sensor), slightly different for each eye (Retinal Disparity), and then the brain analyzes the two slightly different images and puts the two together to give us the final product. Of a necessity such a final result is different, albeit slightly, for any two individuals observing the same image.

BTW, when not looking at a flat image on a screen or print, our camera system (eye lens; retina, optic nerve, occipital lobe of the brain) are able to generate 3D images of the world around us, all the time.

As they say, perception is reality.

I am waiting patiently for you to complete you five lens comparison for the Z-mount.

Fouad

 

[MrHollywood]

…

The next part of it lies with human insecurity; people don't want to admit or talk about their equipment being in any way 'flawed', lest it reflects negatively on their character and abilities as a person, so they introduce more positive spin on things, hence the 'character' of lenses, or the 'warm, rich sound' of vinyl. Etc. Which again is fine, but people would do well to realise, acknowledge and understand this. Subjectivity is great; it's what allows art in the first place, but leave out the pretentiousness and BS. Be honest; just say 'I like the effect this crap old lens produces', or 'I like the scratchiness of vinyl cos it reminds me of when I was a kid hearing my parents LPs', or whatever. Take time to understand your own emotional and even subconscious response to things. Because those are what are going to make you a better artist, not parroting pretentious waffle you read online or hard in a YT video.

This insecurity works both ways, when the owner of a newer, more perfect lens, like the Plena, is compelled to relegate other equipment to the dustbin of history because it doesn’t measure up to a narrow definition of perfection.

Well no, because that's not really happening here, is it? Just the statement of the fact that certain lenses are optically superior. And that the term 'character' is used to cover up flaws. It's much more of an Emperor's New Clothes scenario, with some calling out the Imperial nudity. Nobody is calling for those flawed lenses to be 'consigned to the dustbin of history'. That hasn't happened.

I’m not knocking the Plena - I own one myself. It truly is an improvement over previous 135mm lenses - in some ways. But it’s most often not my chosen lens in actual use, for multiple reasons that have nothing to do with accuracy, sharpness, or relative freedom from aberration.

But you have to accept that is purely down to subjective choices, nothing else. It's because you have a personal preference. Someone else might make a different choice. But nobody could argue that the superior lens isn't superior, as facts trump subjectivity.

Well stated.

Robert

 

[F786]

Photography may not be the art form that can claim the most seminal works of art, but it certainly is the one that has sparked the most nonsensical discussions.

Because it is so accessible to everyone and anyone with just even a cellphone

 

[Ellis Vener]

Photography may not be the art form that can claim the most seminal works of art, but it certainly is the one that has sparked the most nonsensical discussions.

Because it is so accessible to everyone and anyone with just even a cellphone

Eastman (later Eastman Kodak) ad from 1888

What's different now is the invention and commercialization of the internet enables forums like this one.

--
Ellis Vener
To see my work, please visit http://www.ellisvener.com
I am on Instagram @EllisVenerStudio
If you like my question or response, please give a thumbs up. My ego needs the strokes.

 

[MimiVivi]

Okay. Have a nice day!

Well thanks, MrHollywood! You too!

You know, while I understand the conversational appeal of this thread's debate, I don't find much deep artistic utility in it.

The thing is: there are no photographic lenses that render the world as we see it. None. Zip. Zero.

We don't see in flat two-dimensional rectilinear 3:2 squares. We don't see dramatically shallow depths of field. We don't see sharp images "corner-to-corner" in our field of view--to the contrary, the overall "sharp" or acute area of our vision field is a tiny center region, with dramatic falloff in terms of both sharpness and light collection at the periphery. The human experience is always focused on what's immediately in front of you.

The lenses of our eyes are simple single-element devices that project on a curved image plane (the back of your eyeball). By Nikon Z standards, it's a ridiculously flawed optical system ( :-D ) even when it's formed perfectly (i.e. you don't need glasses), hugely prone to every aberration in the book from CA to coma and so forth. Worse, the light-sensitivity of the "photographic medium" your eye lens projects upon--your retina--is (hilariously) unevenly distributed--most dense at the center, except of course for the infamous "blind spot" at the exact center where the light-sensitive structures recede into your optic nerve and there's zero light sensitivity! Imagine that: a camera with a blind hole at the exact center of its sensing media! The human brain does a whole lot of live-action, subjective post processing.

What it means as a photographer: you're always picking a stylized representation. That's literally all we do! That is the craft. What you call "clinical," well, that is a "character," a deep one, a subjectively-chosen one, a representation that is just as far from the reality of human experience as any other a photographer might shoot. A lens that can render a perfect 3:2 rectilinear square with high transmission on a flat media with perfectly-even distribution of light sensitivity? We don't see that. Ever. Couldn't be more different than the human eye or the human experience. The most acute human eyeballs perform a whole lot more like an old Nikon 28mm f/2.8D shot wide-open, mounted on a camera loaded with wrinkled, light-leaked film. (Punctured with a giant hole in the middle! :-D ) Honestly though, even the old 28D has us beat in many, many ways.

So there's no actual "versus" here. It's why photography is an art: you're always neck-deep in the business of subjective representation. Understanding what you're doing beneath a rhetorical scaffolding of "clinical" vs "character" is just that: a rhetorical structure, a story-- one which may help you get where you want to go for one creative project, but may just as easily get in the way of what you're trying to accomplish on another.

There are many, many, many other rhetorical structures you could build--stories you could tell--about which lenses are "useful" or "not" in reaching your particular desired creative result. None of them have any greater or lesser purchase on the reality of our experience; they're all just subjective angles that notice some details in some ways and leave out others. My suggestion: don't box yourself or your creativity into such deep corners. When you're telling a story about things (i.e. "clinical vs character") remember that it's a story. It's not always a bad thing to let a story guide you forward, but at the end of the day the photographic result has to speak to an audience for itself, on its own terms.

¯\_(ツ)_/¯

 

[BasilG]

Photography may not be the art form that can claim the most seminal works of art, but it certainly is the one that has sparked the most nonsensical discussions.

Because it is so accessible to everyone and anyone with just even a cellphone

"My drawing has character because I used cheap crayons" just does not measure up to our discussions here.

 

[Rodenmg]

Photography may not be the art form that can claim the most seminal works of art, but it certainly is the one that has sparked the most nonsensical discussions.

Because it is so accessible to everyone and anyone with just even a cellphone

"My drawing has character because I used cheap crayons" just does not measure up to our discussions here.

Or, how about my drawing has character because I used very expensive crayons.

OR, Maybe this all boils down to like they say “It ain’t what you got that matters but what you do with it.”

--
... Mike
... https://www.flickr.com/photos/198581502@N02/

 

[Rodenmg]

Okay. Have a nice day!

Well thanks, MrHollywood! You too!

You know, while I understand the conversational appeal of this thread's debate, I don't find much deep artistic utility in it.

The thing is: there are no photographic lenses that render the world as we see it. None. Zip. Zero.

We don't see in flat two-dimensional rectilinear 3:2 squares. We don't see dramatically shallow depths of field. We don't see sharp images "corner-to-corner" in our field of view--to the contrary, the overall "sharp" or acute area of our vision field is a tiny center region, with dramatic falloff in terms of both sharpness and light collection at the periphery. The human experience is always focused on what's immediately in front of you.

The lenses of our eyes are simple single-element devices that project on a curved image plane (the back of your eyeball). By Nikon Z standards, it's a ridiculously flawed optical system ( :-D ) even when it's formed perfectly (i.e. you don't need glasses), hugely prone to every aberration in the book from CA to coma and so forth. Worse, the light-sensitivity of the "photographic medium" your eye lens projects upon--your retina--is (hilariously) unevenly distributed--most dense at the center, except of course for the infamous "blind spot" at the exact center where the light-sensitive structures recede into your optic nerve and there's zero light sensitivity! Imagine that: a camera with a blind hole at the exact center of its sensing media! The human brain does a whole lot of live-action, subjective post processing.

What it means as a photographer: you're always picking a stylized representation. That's literally all we do! That is the craft. What you call "clinical," well, that is a "character," a deep one, a subjectively-chosen one, a representation that is just as far from the reality of human experience as any other a photographer might shoot. A lens that can render a perfect 3:2 rectilinear square with high transmission on a flat media with perfectly-even distribution of light sensitivity? We don't see that. Ever. Couldn't be more different than the human eye or the human experience. The most acute human eyeballs perform a whole lot more like an old Nikon 28mm f/2.8D shot wide-open, mounted on a camera loaded with wrinkled, light-leaked film. (Punctured with a giant hole in the middle! :-D ) Honestly though, even the old 28D has us beat in many, many ways.

So there's no actual "versus" here. It's why photography is an art: you're always neck-deep in the business of subjective representation. Understanding what you're doing beneath a rhetorical scaffolding of "clinical" vs "character" is just that: a rhetorical structure, a story-- one which may help you get where you want to go for one creative project, but may just as easily get in the way of what you're trying to accomplish on another.

There are many, many, many other rhetorical structures you could build--stories you could tell--about which lenses are "useful" or "not" in reaching your particular desired creative result. None of them have any greater or lesser purchase on the reality of our experience; they're all just subjective angles that notice some details in some ways and leave out others. My suggestion: don't box yourself or your creativity into such deep corners. When you're telling a story about things (i.e. "clinical vs character") remember that it's a story. It's not always a bad thing to let a story guide you forward, but at the end of the day the photographic result has to speak to an audience for itself, on its own terms.

¯\_(ツ)_/¯

Nice post.

--
... Mike
... https://www.flickr.com/photos/198581502@N02/

 

[j_photo]

It's why photography is an art: you're always neck-deep in the business of subjective representation.

Agree.

 

[Leonard Migliore]

It sure is. My wife is a landscape painter and always works from real life. She'll take a photo of the scene for reference (the paintings are generally unfinished in the field and get touched up in the studio) but needs to draw the scene from life. Stuff painted from a photograph looks different and we can almost always tell. We've tried to articulate exactly what's different but it's almost certainly related to the "one eye versus two eyes" representation of reality. The perspective generated by any lens is different from the perspective perceived by a live viewer.

 

[Rodenmg]

It sure is. My wife is a landscape painter and always works from real life. She'll take a photo of the scene for reference (the paintings are generally unfinished in the field and get touched up in the studio) but needs to draw the scene from life. Stuff painted from a photograph looks different and we can almost always tell. We've tried to articulate exactly what's different but it's almost certainly related to the "one eye versus two eyes" representation of reality. The perspective generated by any lens is different from the perspective perceived by a live viewer.

This is very interesting. I've wondered about the difference in how an artist and photographer view a scene. I know there is a difference and I think.... well I'm not sure what I think.

 

[Mr Bolton]

Photography may not be the art form that can claim the most seminal works of art, but it certainly is the one that has sparked the most nonsensical discussions.

Because it is so accessible to everyone and anyone with just even a cellphone

"My drawing has character because I used cheap crayons" just does not measure up to our discussions here.

Or, how about my drawing has character because I used very expensive crayons.

OR, Maybe this all boils down to like they say “It ain’t what you got that matters but what you do with it.”

Run whatcha brung. The old hot rodders used to say.

 

[anotherMike]

This thread has taken a lot of side roads, and we may be long past the usefulness of it, but I shall continue down the dirt path anyway with these thoughts

It's good in an earlier post you brought up some of the psychological aspects of things. I think this occasionally plays into the "clinical" look description of a lens, but it's not always so simple.

My current thinking (which means it's subject to evolve as I discover more, test more, or simply realize more) is this:

• People are generally defensive about their purchases. If we're talking about modern lenses that are in the fast prime territory, none are cheap and not every forum member is living with infinite discretionary spending ability. So this works both ways - those who dropped a lot on, say, F mount glass for their D850 are likely to defend it to the hills ("I don't see the Z mount lenses being so much better and I think they are clinical") (which is ironic when some of the lenses they just bought were considered - you guessed it - "clinical" compared to older AF-D or AIS glass), and then of course those who invested a truckload of rupee in the latest Z glass aren't really keen on hearing it's no good.
• But biases run deeper than that. Biases can often limit or constrict learning. Since you brought up audio in your earlier post, specifically vinyl, we'll head there briefly once again. I was "in the biz" when CD first came out, and lord it sounded like bloody hell. A vast majority of the engineering types were "but it's perfect - the math says so" or something to that effect. Or "The problem is in the mastering - CD is so much more accurate, what you're hearing is the mastering" - which has some truth to it. But then people started *questioning* the status quo and dug deeper, and we (over time) find out a lot about what we weren't measuring, and what other aspects of audio were causing some of the harshness - and to be quite clear - it's not just one thing - it was several, from the early brick wall filters, the impact of jitter, insufficient sample rate versus the filters we had in the converters at the time, some problems with the early Sony based storage medium, to mastering that was optimized for analog and so forth. But the point was that minds were opened and people learned and things improved. Today, I'm a long retired ex-audiophile - I have no dog in this hunt at all, and honestly could care less - a good recording is a good recording, whether it be put down on 1/2" tape in 1965 or 24/192 digital from yesterday. I could care less - I enjoy some vinyl, I have no problem with well done digital. Good = Good. So I want to get into this concept of open mind/questioning/learning/exploration in the next section of this post to tie things together...

So now let's move back to lenses. A couple of immutable rules that aren't subject to debate:

• It is physically impossible to design a perfect lens.
• Thus all lenses involve tradeoffs, of course of varying degrees of magnitude

So if we say a modern lens is superior objectively so, it actually gets quite interesting, because we have to define what defines "objectively so", and that's where the "art" of lens design being a marriage of science and art come into play. Forgive me as we're about to get deep into the weeds here.

MTF50 measurements are not sufficient to fully categorize a lenses performance envelope; far from it. Really the best they show is a very rough proxy for a generic term of "sharpness".

Optical bench style MTF in the form we see from a manufacturer - a few resolution frequencies plotted against contrast across the frame, is a lot better, but still is *inadequate* for proving a lenses superiority in an absolute, 100% sense.

Optical bench style MTF we would see from the design software - resolution frequency plotted against contrast (but each graph would be at varying field positions) is far more useful, but is rarely found.

And here's where it gets really deep. A manufacturer can decide to design a lens that is as perfect as they can make it from an optical bench MTF perspective. And it may not render that well. Why? The method of measurement - while quite important, doesn't tell us everything. I'm sorry if we're going to get deeper here, but years ago, guys like Jun Hirakawa of Pentax, and Nikon designers including Haruo Sato noted that if you design lens with perfect MTF (and the MTF remember is measuring on a two dimensional plane), you may run into a rendering where the sense of dimension of images in the photograph are flattened slightly. (This is a very, very rough description, I don't feel like writing all night). So these guys - and likely others whom I don't know about - designed for a combination of good MTF performance as well as good rendering performance. As lens design evolved, or rather, as the tools to evaluate lens design evolved, we have things like Nikons "Optia", which allows a designer to simulate the *rendering* of a design - so they can look at what, say, a 1960's Leica or a modern era Zeiss Apo Sonnar, whatever, render like, and this is in addition to their design software that tells them the "objective" MTF data. Nikon is not the only player - I believe Zeiss has this capability, and I'm sure Sigma/Sony/Canon/Tamron do as well. The odds the chinese third party guys have it - not so much, but I can't say for sure. The point here is that it's entirely possible that Nikon *could* design a lens that would "ace" the MTF (optical bench style), where the guys who run designs through Zemax and then talk about the results, would be impressed, but they chose *not* too! Why is that? Because there is more than just MTF on a subject plane.

So this means that even for a very well designed, very high end lens, that it's entirely possible for lens A to render a bit one way, and lens B to render a bit the other. How on earth could you really classify which one is "perfect" - particularly when the very best measurement methodology we have - optical bench MTF - even as much as that gives us - still may not tell the whole story?

Let's take that a bit further. If you're designing a portrait lens, you're likely to trade off, in portrait distance, some ultra high frequency resolution in order to get some OOF transfer qualities and bokeh. This makes sense *for this use case* because someone shooting a portrait, hand held, will never be able to *achieve* the ultra high frequencies that they designer willingly gave up in the portrait distance range, but that same someone would prefer the OOF transfer and bokeh.

But then, how do you quantify bokeh as a grade? How do you quantify OOF transfer?

You can't, so you can't always say, with 100% certainty, one lens is absolutely without question objectively better than the other.

(BTW, OOF transfer can be measured with through-focus MTF, where we look at MTF performance as we from in front of / at / behind the focus point)

So while I am in general in agreement with those who prefer lenses that are well designed, don't impart a lot of "mistakes" onto the sensor so that I have a very nice image to work with in post, I also realize there is always going to be a subjective aspect to performance, and we can't get around that. Thus, it's not possible to ever say lens A is absolutely superior to lens B objectively. You might be able to talk about one lens being generally sharper than another in a general sense, and we do, but for the overall equation, it's tough to say lens A is universally better than lens B from a measurement perspective. It's not like we're a company making precision widgets and we meet .01 picometer accuracy of diameter and our competitor only can do .02

Sorry for the long winded post that likely lost a *lot* of readers....

 

[Lance B]

This thread has taken a lot of side roads, and we may be long past the usefulness of it, but I shall continue down the dirt path anyway with these thoughts

It's good in an earlier post you brought up some of the psychological aspects of things. I think this occasionally plays into the "clinical" look description of a lens, but it's not always so simple.

My current thinking (which means it's subject to evolve as I discover more, test more, or simply realize more) is this:

• People are generally defensive about their purchases. If we're talking about modern lenses that are in the fast prime territory, none are cheap and not every forum member is living with infinite discretionary spending ability. So this works both ways - those who dropped a lot on, say, F mount glass for their D850 are likely to defend it to the hills ("I don't see the Z mount lenses being so much better and I think they are clinical") (which is ironic when some of the lenses they just bought were considered - you guessed it - "clinical" compared to older AF-D or AIS glass), and then of course those who invested a truckload of rupee in the latest Z glass aren't really keen on hearing it's no good.
• But biases run deeper than that. Biases can often limit or constrict learning. Since you brought up audio in your earlier post, specifically vinyl, we'll head there briefly once again. I was "in the biz" when CD first came out, and lord it sounded like bloody hell. A vast majority of the engineering types were "but it's perfect - the math says so" or something to that effect. Or "The problem is in the mastering - CD is so much more accurate, what you're hearing is the mastering" - which has some truth to it. But then people started *questioning* the status quo and dug deeper, and we (over time) find out a lot about what we weren't measuring, and what other aspects of audio were causing some of the harshness - and to be quite clear - it's not just one thing - it was several, from the early brick wall filters, the impact of jitter, insufficient sample rate versus the filters we had in the converters at the time, some problems with the early Sony based storage medium, to mastering that was optimized for analog and so forth. But the point was that minds were opened and people learned and things improved. Today, I'm a long retired ex-audiophile - I have no dog in this hunt at all, and honestly could care less - a good recording is a good recording, whether it be put down on 1/2" tape in 1965 or 24/192 digital from yesterday. I could care less - I enjoy some vinyl, I have no problem with well done digital. Good = Good. So I want to get into this concept of open mind/questioning/learning/exploration in the next section of this post to tie things together...

So now let's move back to lenses. A couple of immutable rules that aren't subject to debate:

• It is physically impossible to design a perfect lens.
• Thus all lenses involve tradeoffs, of course of varying degrees of magnitude

So if we say a modern lens is superior objectively so, it actually gets quite interesting, because we have to define what defines "objectively so", and that's where the "art" of lens design being a marriage of science and art come into play. Forgive me as we're about to get deep into the weeds here.

MTF50 measurements are not sufficient to fully categorize a lenses performance envelope; far from it. Really the best they show is a very rough proxy for a generic term of "sharpness".

Optical bench style MTF in the form we see from a manufacturer - a few resolution frequencies plotted against contrast across the frame, is a lot better, but still is *inadequate* for proving a lenses superiority in an absolute, 100% sense.

Optical bench style MTF we would see from the design software - resolution frequency plotted against contrast (but each graph would be at varying field positions) is far more useful, but is rarely found.

And here's where it gets really deep. A manufacturer can decide to design a lens that is as perfect as they can make it from an optical bench MTF perspective. And it may not render that well. Why? The method of measurement - while quite important, doesn't tell us everything. I'm sorry if we're going to get deeper here, but years ago, guys like Jun Hirakawa of Pentax, and Nikon designers including Haruo Sato noted that if you design lens with perfect MTF (and the MTF remember is measuring on a two dimensional plane), you may run into a rendering where the sense of dimension of images in the photograph are flattened slightly. (This is a very, very rough description, I don't feel like writing all night). So these guys - and likely others whom I don't know about - designed for a combination of good MTF performance as well as good rendering performance. As lens design evolved, or rather, as the tools to evaluate lens design evolved, we have things like Nikons "Optia", which allows a designer to simulate the *rendering* of a design - so they can look at what, say, a 1960's Leica or a modern era Zeiss Apo Sonnar, whatever, render like, and this is in addition to their design software that tells them the "objective" MTF data. Nikon is not the only player - I believe Zeiss has this capability, and I'm sure Sigma/Sony/Canon/Tamron do as well. The odds the chinese third party guys have it - not so much, but I can't say for sure. The point here is that it's entirely possible that Nikon *could* design a lens that would "ace" the MTF (optical bench style), where the guys who run designs through Zemax and then talk about the results, would be impressed, but they chose *not* too! Why is that? Because there is more than just MTF on a subject plane.

So this means that even for a very well designed, very high end lens, that it's entirely possible for lens A to render a bit one way, and lens B to render a bit the other. How on earth could you really classify which one is "perfect" - particularly when the very best measurement methodology we have - optical bench MTF - even as much as that gives us - still may not tell the whole story?

Let's take that a bit further. If you're designing a portrait lens, you're likely to trade off, in portrait distance, some ultra high frequency resolution in order to get some OOF transfer qualities and bokeh. This makes sense *for this use case* because someone shooting a portrait, hand held, will never be able to *achieve* the ultra high frequencies that they designer willingly gave up in the portrait distance range, but that same someone would prefer the OOF transfer and bokeh.

But then, how do you quantify bokeh as a grade? How do you quantify OOF transfer?

You can't, so you can't always say, with 100% certainty, one lens is absolutely without question objectively better than the other.

(BTW, OOF transfer can be measured with through-focus MTF, where we look at MTF performance as we from in front of / at / behind the focus point)

So while I am in general in agreement with those who prefer lenses that are well designed, don't impart a lot of "mistakes" onto the sensor so that I have a very nice image to work with in post, I also realize there is always going to be a subjective aspect to performance, and we can't get around that. Thus, it's not possible to ever say lens A is absolutely superior to lens B objectively. You might be able to talk about one lens being generally sharper than another in a general sense, and we do, but for the overall equation, it's tough to say lens A is universally better than lens B from a measurement perspective. It's not like we're a company making precision widgets and we meet .01 picometer accuracy of diameter and our competitor only can do .02

Sorry for the long winded post that likely lost a *lot* of readers....

Sums it up very well, Mike. I also love the audio analogy, which is also on the money.

 

[TechStrider]

Thank you, anotherMike.

I certainly, and I believe quite a lot of us do as well, really appreciate all that you put into your posts. You are not losing us.

This one is another great one.

You do have a bookmark folder in my browser for Nuanced_Lens_Discussions.