Home · Register · Search · View Winners · Software · Hosting · Software · Join Upload & Sell

Moderated by: Fred Miranda
Username   Password

  New fredmiranda.com Mobile Site
  New Feature: SMS Notification alert
  New Feature: Buy & Sell Watchlist
  

FM Forums | Alternative Gear & Lenses | Join Upload & Sell

1
       2       end
  

Archive 2013 · Micro contrast ?
  
 
eco_bach
Offline

Upload & Sell: Off
p.1 #1 · Micro contrast ?


Ok
Plopped down some cash on the Zeiss 50mm macro after considering the 1.4
I've read extensive reviews elsewhere that talk about 'micro contrast' and the 3d quality of Zeiss glass but have no idea what people are talking about. Can anyone enlighten me or point me to some comparison examples? ie same shot & focal length shot with Zeiss and non Zeiss glass


Even after going thru this long thread
http://www.fredmiranda.com/forum/topic/822469/2

I am very skeptical there is such a thing as a 'Zeiss look'



Apr 25, 2013 at 06:06 PM
RustyBug
Online
• • • • • •
Upload & Sell: On
p.1 #2 · Micro contrast ?


You might try this epic one.

http://www.fredmiranda.com/forum/topic/829238/0?keyword=3d#7701654

Imo, you have to harness the changes in transition rates / zones of the lens in conjunction with your placement of subject. Those changes in transition emulate a bit more strongly how we perceive near/far relationships. Placing one portion of a scene in an area with rapid transitions and another portion of the scene where the lens uses slower transitions creates a delta that is more prominent than a lens that uses more consistent transitions across the entire frame. This exaggerated delta can make it seem like it is in an even more distant plane than normal DOF variance will yield perceptually. (It can be emulated in post also to varying degree of success, but challenging to make look natural).

My observation has indicated that lenses that tend to have this capability are those with mtf sagittal and tangential lines that are congruently aligned to a given point ... and ... that simultaneously have large exit pupils relative to entrance pupil are most eligible candidates. (Personal theory derived from studies of Zeiss lens mtf's that exhibit strong tendencies vs. Zeiss lenses that don't.)

And just because a lens fits those tendencies, the subject distance/placement still needs to align with the transitional variance to get the "3D-ishness" pop to occur at its peak. Zeiss isn't the only mfr to produce lenses with these tendencies, they just seem to do it the most often, and the best ... hence the "Zeiss look" ... but it isn't relegated to Zeiss glass only, just glass that is designed in that manner ... imo.

In the epic thread linked above showed examples where the emulation could be achieved/enhanced in post with non-Zeiss. Unfortunately, many of the examples have since been removed, so it is a bit hit & miss @ examples.


Here's the mtf for the 50/2 vs. the 100/2. Unfortunately the newer data sheets don't include the entrance/exit pupil sizes like the old ones did. (Anybody got good links to the older C/Y stuff?)
If you compare how tightly aligned the sagittal and tangential mtf's are on the 100/2 ... you can see that the 50/2 isn't as congruently aligned.


http://lenses.zeiss.com/content/dam/Photography/new/pdf/en/downloadcenter/datasheets_slr/makroplanart2100.pdf

http://lenses.zeiss.com/content/dam/Photography/new/pdf/en/downloadcenter/datasheets_slr/makroplanart250.pdf


Others can speak to this better than I, but this is what I look for in those lenses that I choose for their "3D-ishness" & micro-contrast drawing style characteristics ... Zeiss, or otherwise.



Apr 25, 2013 at 06:22 PM
philip_pj
Offline
• • • •
Upload & Sell: Off
p.1 #3 · Micro contrast ?


'I am very skeptical there is such a thing as a 'Zeiss look''

Short answer:

Man, you gotta have it in your eyes to see it...

Long answer, with all quotes courtesy of Zeiss:

Micro contrast, often hyphenated, or expressed as one word, consists of the ability to perceive very fine structures in an image, as the term suggests. Interestingly, and this is something Ctein has mentioned in the past, Zeiss also talk about in connection to micro contrast:

'structures, which we can just about see or just cannot see with the naked eye'

Yes, structures you cannot see are very important to the quality of the image, bet you never knew that before today ;-)

'One must always consider the MTF at several spatial frequencies...In real images, it always also depends on what the values at 20 and 40lp/mm are.'

See, when you talk 'micro contrast' you are talking MTF representations of a lens performance. It's exact and all people 'in the know' achnowledge it.

Now, you can actually improve micro contrast somewhat in post processing through edge enhancement. Sadly this does nothing for resolution, and does plenty for potential artifacts. It's my working hypothesis that many small sensor cameras have plenty of this edge enhancement going on, to help provide cover for a lack of resolution, but it's a work in progress. I dare not raise this in the relevant image threads!

Now how to tell if your lens has excellent micro contrast - even if you have not yet learnt to see it:

'If the lens is stopped down, all MTF values increase greatly; the curves are very close to each other at a high value. The MTF values therefore decrease only relatively slowly with increasing spatial frequency. This means excellent edge definition and very good micro contrast right down to the finest structures which can be reproduced by the sensor.'

You mention also the controversial term '3D'. Many people erroneously believe this quality equates to subject isolation, focus fade characteristics and/or bokeh qualities.

It, however, refers to the ability of a lens to faithfully reproduce image objects consistently across spatial frequencies (size of objects in images) and for a given spatial frequency from image centre out to the edges and corners of the image.

'...a flat MTF curve is representative of good contour definition.'

and

'For most image contents the subjective impression of sharpness depends on the
contour definition. The contour definition is high when the curves are flat.'

Now this property remains true of lenses that are not top drawer in terms of MTF performance. Lenses that people perceive as sharp - such as the Contax 80-200/4 - may not have ultra high MTF results, however its flat MTF lines indicate consistent object shaping across size of object and across image space.

Bottom line: rest assured that, even if you do not (yet, there is always hope!) see these qualities in the 50MP, others most assuredly will! It is one of CZ's best ever lenses for small format.



Apr 26, 2013 at 04:13 AM
aleksanderpolo
Offline
• • •
Upload & Sell: Off
p.1 #4 · Micro contrast ?


I like the term "contour definition".

"3D" tends to get muddy when confused with shallow DOF.

The Zeiss look I think is a combination of good contour definition, vibrant (but realistic) color, low veiling glare (due to good coating). Giving one the impression of looking at reality, rather than looking at reality through a glass window (if this analogy make sense).



Apr 26, 2013 at 04:39 AM
sebboh
Offline
• • • • • •
Upload & Sell: Off
p.1 #5 · Micro contrast ?


oh, no. not again.

some people think they see it, some people think they don't.

my advice is not to worry either way.

man, i forgot how many great pics richard had...



Apr 26, 2013 at 05:08 AM
edwardkaraa
Offline
• • • • •
Upload & Sell: Off
p.1 #6 · Micro contrast ?


I have to say, I see very little 3D from the current Zeiss lines. What made Zeiss famous for 3D was the Contax line. I think Zeiss lost it in their quest to produce clinical lenses with corner to corner sharpness.


Apr 26, 2013 at 05:34 AM
philber
Offline
• • • • •
Upload & Sell: On
p.1 #7 · Micro contrast ?


Sorry to disagree, Edward. I see more 3D in the recent Z* lenses than in the previous C/Y line. But this increased 3D is less spectacular, because of increased resolution of fine detail. A typical example is the improved 3D from Z* 35 f:2.0 to Z* 35 f:1.4, even though the f:2.0 is more spectacular.


Apr 26, 2013 at 07:18 AM
zhangyue
Offline
• • • •
Upload & Sell: Off
p.1 #8 · Micro contrast ?


sebboh wrote:
oh, no. not again.

some people think they see it, some people think they don't.

my advice is not to worry either way.

man, i forgot how many great pics richard had...


+1 for not worry about it.

You can't force me to think it is 3D, and I can't persuade you it is not 3D So what

But who is Richard?




Apr 26, 2013 at 07:24 AM
carstenw
Offline
• • • • • •
Upload & Sell: Off
p.1 #9 · Micro contrast ?


The 50P and 85P Z lenses definitely have some 3D ability, as does the 35/2, and to a lesser extent, the 35/1.4. The 21 can produce it, and the 100/2.


Apr 26, 2013 at 07:27 AM
carstenw
Offline
• • • • • •
Upload & Sell: Off
p.1 #10 · Micro contrast ?


zhangyue wrote:
+1 for not worry about it.

You can't force me to think it is 3D, and I can't persuade you it is not 3D So what

But who is Richard?


Richard is brainiac, but his account got locked due to a disagreement, and he doesn't hang around here any more.



Apr 26, 2013 at 07:28 AM
 

Search in Used Dept. 



edwardkaraa
Offline
• • • • •
Upload & Sell: Off
p.1 #11 · Micro contrast ?


philber wrote:
Sorry to disagree, Edward. I see more 3D in the recent Z* lenses than in the previous C/Y line. But this increased 3D is less spectacular, because of increased resolution of fine detail. A typical example is the improved 3D from Z* 35 f:2.0 to Z* 35 f:1.4, even though the f:2.0 is more spectacular.


Of course, we can only compare equivalent lenses. To my eyes, the Contax has visibly more 3D in the following lenses:

21/2.8, 25/2.8, 28/2, 35/1.4, 100/2 (P vs MP).

I think the 50/1.4 and 85/1.4 must be quite similar in this respect between CY and Zeiss, even though the Zeiss 50/1.4 has a much worse WO performance than the CY.



Apr 26, 2013 at 07:40 AM
AhamB
Offline
• • • •
Upload & Sell: On
p.1 #12 · Micro contrast ?


sebboh wrote:
oh, no. not again.

some people think they see it, some people think they don't.

my advice is not to worry either way.

man, i forgot how many great pics richard had...


Agreed. If you don't see anything special in the images made with your Zeiss 50/1.4 compared to your other lenses, we can't help you see it. For me it was immediately evident with my Contax Zeiss 28/2.8, 50/1.4 and 100/2.8 though. They all have a way of rendering that is distinctly different from the other lenses I have and I can recognize that signature look very often in images I see, esp. in that old thread you linked to.



Apr 26, 2013 at 08:31 AM
jj birder
Offline
• •
Upload & Sell: Off
p.1 #13 · Micro contrast ?


eco_bach wrote:
Ok
Plopped down some cash on the Zeiss 50mm macro after considering the 1.4
I've read extensive reviews elsewhere that talk about 'micro contrast' and the 3d quality of Zeiss glass but have no idea what people are talking about. Can anyone enlighten me or point me to some comparison examples? ie same shot & focal length shot with Zeiss and non Zeiss glass

Even after going thru this long thread
http://www.fredmiranda.com/forum/topic/822469/2

I am very skeptical there is such a thing as a 'Zeiss look'


Micro contrast: you can have global contrast of the whole image and on a smaller scale you can have micro contrast between details and tones within the image.

3D effect: sometimes a subject looks distinct from its background and/or foreground.

Zeiss look: just as you can have a Holga look (vignetting and flare and softness) you can have a Zeiss look which tends to be sharp, low distortion and detailed.

All three are tendencies and not absolutes. All three tendencies can be shown by other lenses by other good manufacturers. All three are (to a greater or lesser extent) difficult to define. And all three can fill pages and pages of obscure arguments in internet forums that rarely if ever get anywhere.

All that matters to me is that Zeiss makes fine lenses. The ones I have are all great (G28/45/90, CY 50 1.7). Enjoy your lens. It will most likely be good. Take pictures with it. If you like it keep it and if you don't then sell it.



Apr 26, 2013 at 09:30 AM
carstenw
Offline
• • • • • •
Upload & Sell: Off
p.1 #14 · Micro contrast ?


Global contrast: the ability to reproduce pure white and pure black somewhere in the image.
Micro-contrast: the ability to reproduce pure white and pure black right next to each other.

All real lenses will leak some white into the black and some black into the white, and there will be some zone of transition (scattering, I suppose). Zeiss lenses are known for having high micro-contrast, in general. Leica and Schneider and a few of the best other lenses can also do this, but none as consistently as Zeiss, to my knowledge.

Note that micro-contrast is not strongly tied to resolution, although they are clearly related. Zeiss lenses will tend to have higher micro-contrast than Leica lenses, but lower resolution in many cases. The Z 35/1.4 and 35/1.4R are examples of this (I own both). The Leica can reproduce finer detail, but the Zeiss has a more punchy image.



Apr 26, 2013 at 12:15 PM
you2
Offline
• • •
Upload & Sell: On
p.1 #15 · Micro contrast ?


One thing that is amusing about the zeiss note quoted in post #3 is that the lens might actually emphasis/capture subtle tones that the naked eye miss. One advantage of the eye is that it can cover a much larger dynamic range than most digital sensors but I often wonder if that came at a cost. I guess I personally never really tried to go back and examine a scene taken in a photo-graph to see if I just didn't notice what the lens capatured with regards to colour transitions or if the lens was actually able to 'magnify' that transition.


Apr 26, 2013 at 12:34 PM
eco_bach
Offline

Upload & Sell: Off
p.1 #16 · Micro contrast ?


Thanks for the great info. From my initial reading of all the posts regarding '3D' I propose that the term be stricken from any serious photographers vocabulary! I mean seriously, i have never come across a term being used in so many ways!
Micro contrast on the other hand is something that can be measured objectively it seems. Thanks for the clarification re microcontrast vs sharpness.



Apr 26, 2013 at 03:05 PM
AhamB
Offline
• • • •
Upload & Sell: On
p.1 #17 · Micro contrast ?


eco_bach wrote:
Micro contrast on the other hand is something that can be measured objectively it seems. Thanks for the clarification re microcontrast vs sharpness.


Don't get hung up on measurements and numbers. They are the least interesting things about lenses -- it's about the images that they deliver and that's the only thing that gives satisfaction. It's not possible to really derive what gives Zeiss lenses their characteristic look simply by looking at MTF charts.

One more thing to confuse you even further: resolution and sharpness are two different things. Resolution just means the scale of details that are resolved (distinguishable) by the lens. An image with high resolution with low acutance/microcontrast doesn't give an impression of great sharpness though. A lens with less resolution but higher microcontrast will subjectively look sharper. When you sharpen an image digitally you're just enhancing the acutance/microcontrast but not increasing resolution.



Apr 26, 2013 at 03:36 PM
RustyBug
Online
• • • • • •
Upload & Sell: On
p.1 #18 · Micro contrast ?


If you do some study on Trompe-l'il you'll find some insight into the creation of the 3D-ishness illusion/perception having a long history in the 2D media (i.e. paint, drawing, etc.) for centuries.

Going back to the aspect of transition rates, planes of focus, dof, etc. there is some varying degree of ability to create/render similar perception/illusion depending upon lens design and subject distance/area placement particularly in context with accompanying pp that such mtf/exit pupil characteristics will tolerate. Those who predated photography, still created the illusion based on their understanding of the human visual response physiology.

Different lens designs are intended to harness these attributes similarly (to varying degrees). This is where I think Zeiss has spent a greater amount of time/effort than most other mfr's in incorporating this thought process into some of their lens designs. In some regard, progressive bifocals (which Zeiss also makes) hint (inversely) at the selective distance zones/variable transition rate usage principle.

In the photographic community ... yup, there is a tremendous variance upon the attempt to define "3D-ishness". Personally, I prefer to simply consider it the craft of Trompe-l'il ... the same as the masters before us, only within the realm of our chosen photographic medium.

As to seeing it ... some paintings/murals generate the illusion very well and fool people greatly as their perception responds to the image. Depending on the person and the image contains a degree of variance at how much the illusion succeeds or not. As it is with non-photographic 2D medium, so it is also within the photographic 2D medium ... i.e. some see it, some don't.



Apr 26, 2013 at 03:36 PM
theSuede
Offline
• • • •
Upload & Sell: Off
p.1 #19 · Micro contrast ?


carstenw wrote:
Global contrast: the ability to reproduce pure white and pure black somewhere in the image.
Micro-contrast: the ability to reproduce pure white and pure black right next to each other.

All real lenses will leak some white into the black and some black into the white, and there will be some zone of transition (scattering, I suppose). Zeiss lenses are known for having high micro-contrast, in general. Leica and Schneider and a few of the best other lenses can also do this, but none as consistently as Zeiss, to my knowledge.

Note that micro-contrast is not strongly tied to resolution, although they are
...Show more

Actually I'd want to correct the middle part of this statement, since it affects all sharpening and contrast post processing...
Black does not "bleed". It can only be bled into, since there's no such thing as "negative light" - at least not until you go into deep physics that have no real meaning to a photographer (or approximately 6,499,999,900 out of the 6.5 billion people living on this earth either for this matter... ) - You can however have phase cancellations, and this is what gives the black rings in between the bright rings in a diffraction circles.

Points where light is strong can be diluted into neighboring areas - this takes away some of the intensity in the peak of the point. But this lowering of intensity is mostly inconsequential for almost all photographic purposes.

But small areas/points/lines that are darker than their surroundings get "bled into".

Real sharpening, the kind of sharpening that actually CAN restore the elusive concept of "micro-contrast" is almost exclusively darkening of areas/pixels darker than its' neighborhood - this is real "capture sharpening".

Sharpening like normal unsharp mask in photoshop, on normal sRGB or Adobe RGB images, brightens opposite edges to increase the perceptual sharpness by increasing edge contrast, but is often feels less "natural". And it definitely isn't "natural".



Apr 26, 2013 at 06:21 PM
itai195
Offline
• • •
Upload & Sell: Off
p.1 #20 · Micro contrast ?


Neat, the mid-2013 edition of this thread.


Apr 26, 2013 at 06:32 PM
1
       2       end




FM Forums | Alternative Gear & Lenses | Join Upload & Sell

1
       2       end
    
 

You are not logged in. Login or Register

Username   Password    Retrive password