Low Element Count Lenses, 3D pop, and Micro-contrast -- My Theory

[michaelwj]

Here is an interesting article... A couple quotes that supports my original position

"...adding additional elements, each designed to correct for specific aberrations, lens manufacturers can minimise their effects.
[...]
Adding additional elements isn’t a perfect fix. Every time light is transmitted from one lens to another a little bit of light is lost. The more elements in a lens, the more light and colour information that is lost in transmission. There is a trade off between correcting for optical aberrations and preserving information.

[...]
3D Rendition and Micro-Contrast
Older lenses have far fewer elements than modern lenses. These makes them more prone to optical aberrations and, in particular, it means they often have very soft edges. On the other hand, they can have some incredibly pleasing characteristics. Unlike resolution or sharpness, these characteristics are a lot more difficult to measure with a chart. "

Micro-contrast is the small amounts of tonal and colour variance between details on a subject. It’s an incredibly subtle effect but it is often what sets excellent glass—like Leica, Zeiss, Canon L series, medium-format or large-format lenses—apart from cheaper lenses. Micro-contrast is what gives areas of consistent colour a realistic and accurate texture. It is among the first detail to be lost when light passes through too many elements. "

Worth a read
Here Is What to Look For When You Buy Photography Lenses
https://photography.tutsplus.com/tu...or-when-you-buy-photography-lenses--cms-27047

The source you cite has no authority on these matters, and describes themselves as a photographer, adventurer, and man of mystery.
They are incorrect. The number of elements has nothing to do with “micro-contrast” or “3D pop”. I will say again, correlation does not equal causality.

The Zeiss Biogons and Distagons both have huge numbers of elements in heaps of groups, yet are often thrown in the “3D pop” and “micro contrast” heap.

 

[teddy]

Back to the 3D or 'pop' look; some really poor lenses are great for this. Curvature of focus, naturally poor lenses quality (edge blur), maybe even (as above say) 'under-correction of some optical faults,' less sophisticated quality of the glass maybe in the end encourage 3D and 'pop.'

This is what I've been saying. Astigmatism, curvature of field, vignetting and myriad combinations of all. This is a factor on the "3-D Pop".
Such a simplistic idea to the solution, but because it's banal - I get no feedback... A good thread anyhow.

 

[cboy]

Dont know what people are on about here. Lens manufactures are purposely boring us with clinical lenses? Seriously have you checked out the SL lenses have amazing 3d depth to them despite having numerous glass elements. How much elements is too much? Perhaps the lens designers here can tell me. Peter Karbe noted that the best lenses are those that are able to higly resolve at the lower contrast area of a scene ... https://youtu.be/G_Rgs8otVC0

 

[kbb]

"3D Pop", or what I think people mean when they write the term, comes from lighting and composition. Yes, some lenses are flat and low contrast, others give a more snappy rendition. We've known this for 100 years.
The term Microcontrast, which by it's construction actually translates as 'extremely small contrast', is a now-worthless term here on the forums because there are at least two separate and incompatible definitions being used. Many think it means the clear rendition of extremely small details, but many others blather on about the separation of tones and colors. Which is it?

 

[gavinlg]

Dont know what people are on about here. Lens manufactures are purposely boring us with clinical lenses? Seriously have you checked out the SL lenses have amazing 3d depth to them despite having numerous glass elements. How much elements is too much? Perhaps the lens designers here can tell me. Peter Karbe noted that the best lenses are those that are able to higly resolve at the lower contrast area of a scene ... https://youtu.be/G_Rgs8otVC0

It's kind of like the Sigma Art lenses which are technical masterpieces, but 'something' about they way they draw is obviously quite flat to me. In the same way, the (what I would call) golden era lenses of the 70s/80s/90s with relatively simple optical formulas and leaded glass may not be as technically sharp, but 'something' about the way they draw has a depth I don't tend to see with the Sigmas.
I originally rejected this idea but have in the last few years after going through tens of dozens of lenses have come around to it. A really good example is the Voigtlander 58mm f1.4 Nokton vs a sigma 50mm f1.4 art.

"3D Pop", or what I think people mean when they write the term, comes from lighting and composition.

Yes, 100%. But there's definitely differences in lens rendering too. My subjective view is there's a sweet spot between under corrected and technically perfect where rendering is most natural.

The term Microcontrast, which by it's construction actually translates as 'extremely small contrast', is a now-worthless term here on the forums because there are at least two separate and incompatible definitions being used. Many think it means the clear rendition of extremely small details, but many others blather on about the separation of tones and colors. Which is it?

They could quite easily be the same thing, given they're at the least somewhat interrelated definitions. I think it's fairly obvious that designs like the Contax/kyocera era lenses (Contax G and Contax SLR lenses) have a noticeably higher microcontrast (wether that be in separation of tones or clear rendition of details) than the equivalent OM zuiko lenses of the same period, for instance.

 

[NickTrop]

Re-reading this old thread, some argued those I've cited are not qualified to speak to the subject, as advocates of simple lens designs are not optical engineers. How about these quotes from Nikon lens designer Haruo Sato, who designed the surprisingly great, low element count (for a zoom) Nikon 6 element/6 group 28-80mm f3.3-5.6 kit zoom found on their later film SLRs?
IV. More lens elements are a "necessary evil"
-- As a young designer, a number of outstanding predecessors and mentors shared with me their knowledge of optical design. Among the tidbits passed along, I often remember hearing that "more lens elements are a necessary evil".

-- I have spent my entire career designing lenses to be as simple as possible and to utilize the fewest number of lens elements possible.

-- the less experience a designer has, the more they may think that simply increasing the number of lens elements will improve the design, but they then discover that aberrations are not compensated as well as they expected and find themselves caught in a dilemma.

-- Have you never used a lens, such as one with a six-elements-in-two-groups Dagor (Doppel-Anastigmat Görz) structure or a three-elements-in-three-groups triplet structure, that would seem to offer poor aberration performance but actually rendered images better than did a seven-elements-in-six-groups Gauss structure?

-- MTF cannot be used to determine whether or not increasing the number of lens elements with this lens would be beneficial or harmful. That is why I often use cemented lens elements and always try to achieve designs that use the fewest number of lens elements possible.

Although Mr Sato-san doesn't tie "3D quality" to fewer elements, it's interesting he does make mention to this phenomenon at the end of the article:

-- I am of the opinion that current evaluation methods for imaging optics are not sufficient to judge the performance of lenses... As we all know, the subjects of both photos and video are three dimensional. That means that image formation should also be evaluated in three dimensions. The performance of imaging optics must be evaluated based on their three-dimensional characteristics. As for optical design as well, I had thought that a time when we are able to completely control three-dimensional optical characteristics would naturally come.

NIKKOR - The Thousand and One Nights No.63 | NIKKOR - The Thousand and One Nights | Nikon Consumer

 

[CMur12]

Good to see you, Nick.

Though I can't back it up with science, I've always felt that the simplest lens formulation that will do the job is best.

So, I bought a TLR with a simple triplet lens (3 elements/3 groups) for portraiture, as it seemed a much better solution than putting a soft-focus filter onto a sharp lens.

I really like Tessar-formula lenses, at least for medium format TLRs. At wider apertures, the performance characteristics are more desirable for portraiture, while at smaller apertures, they are very sharp, as for landscape photography.

I imagine that more complex lens formulations, at least for increased resolution, are called for with modern high-resolution digital sensors.

- Murray

 

[pgk]

Designing a lens is a purely technical process. I have empirically designed lenses from the early days of photography right through to current stste-of-the-art aspheric designs. And in between are a myriad of lenses enabled by the technological understanding and glass availability of their times (of which Dennis Taylor's 'Cooke' design is a very good example). Despite all the chatter about subjectively defined aspects such as micro-contrast, there is no magic about lenses; most consist of glass ground spherically or aspherically and the outcomes are known, via software, before they are even prototyped (I have a friend who is a lens designer and when I asked him about an early lens design he provided me with the theoretical MTF/distortion/etc., info simply from inputting its optical design).

The 'problem' with photographic lenses is not design but manufacturing which is dependant on quality control, which is expensive as it requires trained people and precision adjustability being possible in the lens itself. The higher the quality control, the closer the lens is to its design parameters. And as an example, high-end cine lenses are very expensive even compared to stills lenses. So there will be some variation between lenses of the same type and some may be more precisely assembled than others.

Then there's the subject matter and lighting .....

 

[Freakscene]

Designing a lens is a purely technical process. I have empirically designed lenses from the early days of photography right through to current stste-of-the-art aspheric designs. And in between are a myriad of lenses enabled by the technological understanding and glass availability of their times (of which Dennis Taylor's 'Cooke' design is a very good example). Despite all the chatter about subjectively defined aspects such as micro-contrast, there is no magic about lenses; most consist of glass ground spherically or aspherically and the outcomes are known, via software, before they are even prototyped (I have a friend who is a lens designer and when I asked him about an early lens design he provided me with the theoretical MTF/distortion/etc., info simply from inputting its optical design).

The 'problem' with photographic lenses is not design but manufacturing which is dependant on quality control, which is expensive as it requires trained people and precision adjustability being possible in the lens itself. The higher the quality control, the closer the lens is to its design parameters. And as an example, high-end cine lenses are very expensive even compared to stills lenses. So there will be some variation between lenses of the same type and some may be more precisely assembled than others.

Then there's the subject matter and lighting .....

Microcontrast is not subjective. It is just small structure (20+lp/mm) MTF. Anyone who says lenses do things that can’t be quantified either hasn’t seen enough data or doesn’t know what it means.

 

[sojournerphoto]

Microcontrast is not subjective. It is just small structure (20+lp/mm) MTF. Anyone who says lenses do things that can’t be quantified either hasn’t seen enough data or doesn’t know what it means.

Agree. Noting that quality control and consistency and precision in manufacturing have transformed what is actually generally available now - Sigma Art being the first example.

Otoh, I don’t like hulking big lenses…

 

[Freakscene]

Otoh, I don’t like hulking big lenses…

This is why I stick with Leica M, particularly for my work, even if their lenses are far from ‘best’ these days.

 

[raydm6]

I still remember the feeling transitioning from a 3-lens Hasselblad system to a Leica M6 and 35 v4 Summicron. What a contrast in handling!

 

[pgk]

Microcontrast is not subjective.

Unfortunately many still think that it is. Alongside thinking that 'bokeh' isn't understood in design terms, and that low contrast lenses somehow compress high contrast scenes!

 

[35photo]

Agree. Noting that quality control and consistency and precision in manufacturing have transformed what is actually generally available now - Sigma Art being the first example.

Otoh, I don’t like hulking big lenses…

Exactly the reason why I got into Leica M stuff 25 years ago... could stand the size lenses were getting and wanted to be as compact as possible to be able to carry around a camera all the time.