The concept of micro-contrast

[p.giannakis]

I've been following a discussion on the book-of-faces regarding micro-contrast. There seems to be some anxiety regarding the optical performance of lenses in that area - which ones are better, which ones not so good etc...

I've never heard of this concept before I joined some Facebook groups some years back. Never came across it in any of the magazines I was reading on the 80s and 90s and I don't see it being discussed in this forum either. I am not aware of any micro-contrast test comparison.

If I believe AI, first one who planted this idea was E. Puts in his discussion regarding Leica lenses.

I just wanted to get your views about it - to me sounds like an elusive concept that never came across it and never cared about it either.

 

[mtnbkr]

The concept predates AI but I've never been able to get a clear example of it where I could see the difference. It always struck me as a nitpick or a way to chestbeat about one lens over another.

Chris

 

[Freakscene]

Microcontrast is a way to describe how the small image size MTF tracks - are the 20 and 40 lp/mm traces for a lens low, moderate or high? Leica used to be the best at this, but modern lens design, mirrorless mounts and customers driven by internet fuelled breathlessness have pushed all manufacturers to have at least one line of ultra high performance lenses. The acceptance that regular prime lenses can be huge and expensive too, has had a massive effect. The Nikkor Z 50mm F/1.2 S weighs over 1 kg and has an 82mm filter thread. The Leica 50mm Apo-Summicron is slightly optically worse, but weighs 300g and has a 39mm filter. Leica lenses were always small and in the SLR days those lenses were always bigger, but this is absurd, even with everything a modern lens needs to incorporate. I know which I’d prefer to work with.

Read this thread: New "old Design" from Leica, 50mm F1.4 Summilux

Ultimately resolution and contrast are the same thing. Microcontrast is just a way to describe how small a structure in a photo can be better or less well resolved.

 

[peterm1]

I am not entirely sure what it means either. But I suspect that it might be something akin to the effect produced by some software filters in Lightroom and other image editors, named the "Clarity" filter in Lightroom and Corel Paintshop Pro (not sure about Photoshop) and "Local Contrast" in some others. I understand these work mainly on mid tonal ranges. They enhance the "crispness" of the image creating an effect of higher resolution which is different to "sharpness" alone. In any event in my experience some lenses seem to have the ability to produce images which might have a similar effect I think. For example, I have some Zeiss lenses which are remarkably "crisp" - a combination perhaps of sharpness, tonality and color rendering which creates something which I suspect is put down to micro contrast but as I say I am unsure.

 

[Freakscene]

I am not entirely sure what it means either. But I suspect that it might be something akin to the effect produced by some software filters in Lightroom and other image editors, named the "Clarity" filter in Lightroom and Corel Paintshop Pro (not sure about Photoshop) and "Local Contrast" in some others. I understand these work mainly on mid tonal ranges. They enhance the "crispness" of the image creating an effect of higher resolution which is different to "sharpness" alone. In any event in my experience some lenses seem to have the ability to produce images which might have a similar effect I think. For example, I have some Zeiss lenses which are remarkably "crisp" - a combination perhaps of sharpness, tonality and color rendering which creates something which I suspect is put down to micro contrast but as I say I am unsure.

The Clarity tool works on large structure contrast. Microcontrast is just about how well small or very small structures in the image are differentiated.

 

[peterm1]

Just found this. I am not sure if this post on another site helps or not. I can see some differences in some photos but to me it is mostly far too subtle to make any generalized conclusions. its like asking how many angels can dance on the head of a pin!

Micro-Contrast, Is It Real? - Samples With Lens Comparisons | Alik Griffin

Micro-contrast: see how it impacts image quality, depth, and visual impact. Is it real, or just a myth? Dive into the science and art with sample images.

alikgriffin.com

 

[Freakscene]

Just found this. I am not sure if this post on another site helps or not. I can see some differences in some photos but to me it is mostly far too subtle to make any generalized conclusions. its like asking how many angels can dance on the head of a pin!

Micro-Contrast, Is It Real? - Samples With Lens Comparisons | Alik Griffin

Micro-contrast: see how it impacts image quality, depth, and visual impact. Is it real, or just a myth? Dive into the science and art with sample images.

alikgriffin.com

That article has several very notable problems. The photos are reasonable examples, but much of the analysis is totally wrong.

 

[mdarnton]

The first time I was aware of it was in the 80s with one of my OM-1 lenses against my other much older RF lenses. To me at the time, put in modern terms in retrospect, it looked like too much digital sharpening, nervous, not smooth. I can definitely see the effects when I focus my old lenses vs new using my magnified view on my Nikon Z5. Basically I think that classic "glow" is another more specialized statement of relatively low microcontrast. These days everything's got high microcontrast, which is why a huge percentage of my pix are shot with older lenses and I use very little digital sharpening. Some of the best modern lenses make me very uncomfortable looking at their results. And that's why my favorite large format lenses are Tessars not stopped down much.

That's my take on it, anyway. As Freakscene mentioned, MTF curves are the scientific statement of it

 

[peterm1]

The first time I was aware of it was in the 80s with one of my OM-1 lenses against my other much older RF lenses. To me at the time, put in modern terms in retrospect, it looked like too much digital sharpening, nervous, not smooth. I can definitely see the effects when I focus my old lenses vs new using my magnified view on my Nikon Z5. Basically I think that classic "glow" is another more specialized statement of relatively low microcontrast. These days everything's got high microcontrast, which is why a huge percentage of my pix are shot with older lenses and I use very little digital sharpening. Some of the best modern lenses make me very uncomfortable looking at their results. And that's why my favorite large format lenses are Tessars not stopped down much.

That's my take on it, anyway. As Freakscene mentioned, MTF curves are the scientific statement of it

As an aside - i.e. about digital sharpening. I have seldom been very happy with most traditional sharpening tools where it is very easy to become "heavy handed" and obvious. Instead for some reason I prefer the "look" conferred by an old method of sharpening using the "layers" tool in Photoshop (or Corel Paintshop Pro which I use). It's a bit more convoluted but once you get the hang of it still quick and much more flexible. Some modern AI sharpening tools are better still I believe though I do not own any editor that can do this.

The method I often use involves first creating a duplicate copy of the image to be sharpened in a new layer. Then apply to the new layer an effect called (in Corel PSP and Photoshop) "High Pass" filter. This filter converts the new image layer to monochrome and highlights any edges in the new layer which now becomes a kind of sharpening mask. (Which I believe is similar to how a conventional sharpening filter works "behind the scenes".) The intensity of the high pass filter can be adjusted by specifying the number of pixels width the edge effect is to be. Then back in the layers tool the layer blending mode is changed from "normal" to "overlay" so the sharpening mask is hidden and the look of the final, sharpened image is revealed. This process has the effect of subtly sharpening the image's edges. If the sharpening is too harsh, the opacity slider can be slid back from 100% to a lower number. And if only parts of the image are to be sharpened the "erase" brush can be used to erase the top layer in areas where sharpening is not desirable. The two images can then be flattened back into a single layer.

All of this is far easier and faster to do than to describe and the benefit is that the overall sharpening effect is effective, yet can be considerably more subtle and selective than a normal simple application of a sharpening tool.

 

[boojum]

My pinheaded understanding is that microcontrast describes the subtle gradations of color and shape in the image. Is there a band of colors in the change or does it seem like just a few? Now if I am off base here please tell me. And it is the good coupling of lens and sensor. A great lens with a lousy sensor or the other way around just does not work.

I am impressed with what the X2D does and I will post what I think are good examples. Correct me if I am wrong. All of these can be double-clicked to bring you to max enlargement on Flickr. The final one of the Oregon Responder has just a nice span of shades of white without losing detail within the white regardless of its brightness. While the RAW files are 16 bit, and that is a huge palette, the JPG's are, of course, 8 bit. These are SOOC. As always, YMMV. Yeah, nautical stuff. There's a lot of it around here.

B0000719 by West Phalia, on Flickr

B0000862 by West Phalia, on Flickr

B0000029 by West Phalia, on Flickr​

 

[boojum]

And then this one of the Flower of St. Petersburg, the dear Irina, here sharing a Caprese Salad in Seattle. I am still impressed at the sharpness and accuracy of this lens while still being flattering. I'll add another of my friend Noel, a renowned water colorist.

This is all doable with other lenses and cameras but I need all the help I can get.

B0001358 by West Phalia, on Flickr

B0000389 by West Phalia, on Flickr​

 

[p.giannakis]

And then this one of the Flower of St. Petersburg, the dear Irina, here sharing a Caprese Salad in Seattle. I am still impressed at the sharpness and accuracy of this lens while still being flattering. I'll add another of my friend Noel, a renowned water colorist.

This is all doable with other lenses and cameras but I need all the help I can get.

B0001358 by West Phalia, on Flickr

B0000389 by West Phalia, on Flickr​

Beautiful portraits.

 

[Wenge]

yes those are very nice portraits... while micro-contrast I think is there, but also on exceptional lens it shows it.

My Leica 35 Summicron has had this "microcontrast" thing on most cameras I've tried it on (but not all). My V3 Canada, it was best on SL2-S but sold the camera, it's also great on newer Sony's; still not sold it, best lens I never sold imo. I think 'microcontrast' is a lens that renders properly where you have to add 'less' sharpening' rather than more, and you know it when you see it.

I see that is the X2D w/55, and since I already have the 45P/X2D, didn't get the 55 but I would guess it's similar, while bokeh is exceptional in these. Well done

 

[boojum]

Thank you both. I was very lucky with each portrait. First to know these people and second to catch a moment that was a good one. And that camera, I just love it. I was unsettled when I bought it. It cost too much. But as soon as I started shooting with it I understood why it costs what it does. And it has made what I shoot look that much better, even the mediocre stuff.

I just came back from a night out at a very small venue where some old friends were playing in a rock quartet. I used up a battery, that's hundreds of photos. I promise to inflict some on you in a few days. ;o)

 

[Wenge]

as a fellow rocker, yes pls share lol
(edit, I also have 90/3.2 is butter-smooth also wide open you might like, rented mine before buying)

 

[boojum]

as a fellow rocker, yes pls share lol
(edit, I also have 90/3.2 is butter-smooth also wide open you might like, rented mine before buying)

I had the XCD 55V but the 120 3.5 macro did the heavy lifting. It was a small venue and the musicians were floor level. I would have had to stand in front of 25% of the audience to shoot with the 55 and at the edge of the "stage." So I sat on my ass and shot with the 120. Some 55. 236 images. If I get five good ones I will be happy. All shot at ISO 25,600 which the X2D does quite well.

They are uploading to Flickr now.

 

[Richard G]

Like Justice Potter Stewart on obscenity, I know it (microcontrast) when I see it. Or at least thought I did as I thought it might actually be a thing. It appears now it may very well not be a thing. When I did think I'd seen it, invariably it was a shot taken on film with my 90 Elmarit-M 2.8. Sharpness can't be the only thing about that lens, there is some extra bite in those shots. Perhaps that was microcontrast I was seeing. I'd rather admit to seeing something which turns out not to be microcontrast, if that doesn't exist, than admit to recognising pornography when I see it, as I'd be admitting I'd seen it....

I still reckon there is soomething about film, and I've seen this bite in shots with my Konica Hexar on HP5 plus. Perhaps microcontrast is something about negatives, not lenses.....?

 

[p.giannakis]

Perhaps microcontrast is something about negatives, not lenses.....?

Or exposure? Film and developer combination? Aperture value? Somehow I more tempted to attribute subtle changes in tonal range and contrast to these factors rather than the lens. But it looks like people have more info than me on this subject.

 

[Freakscene]

Or exposure? Film and developer combination? Aperture value? Somehow I more tempted to attribute subtle changes in tonal range and contrast to these factors rather than the lens. But it looks like people have more info than me on this subject.

You are overcomplicating it. You can measure it in a photo, on a negative or by optical means through a lens. Microcontrast is simply the capacity of the system to capture contrast at fine image scales.

 

[Richard G]

I seem to remember something about the differing density of distribution of silver halide crystals along the borders of contrasting elements on a negative. That may not be microcontrast but might be what I like in a photo shot on film.