What is Micro Contrast? A Blind Test to Help Define It for Once

Discussion in 'Philosophy' started by jack_lam|1, Jul 13, 2020.

  1. As I am doing a research on lens character and the preferred esthetics of lenses, I am increasingly puzzled by the concept of "micro contrast". It is such a controversial topic. Some photographers consider it the ultimate lens character, the holy grail of quality lens. Others dismiss it as sneak oil - a redundant concept that can be more accurately described by existing scientific terms.


    The most interesting part is, we don't seem to agree on the very definition of micro contrast. Many believe that it is unmeasurable. They say micro contrast is more than just contrast, sharpness, or resolution. It is the beauty of detailed tonal transition from bright to dark. Some look at micro contrast with a zen-like approach and insist it is something to meant be felt, not measured in numbers. It is the extra oomph. The FORCE. Something that is only seen by discerning eyes.


    One can only imagine, a simple blind test can help lead us to a consensus on the definition of micro contrast. But I have yet to see such a blind test on the inter-web. So here it comes.


    I shot the following tabletop scene with TEN 50mm lenses. All ten lenses are widely-loved on their own right. They come from a variety of vintage with varying element counts. Some are very expensive cinema lenses. Some are less expensive common lenses. There are no bad lens in this line-up.


    Detailed method:


    At shot at f/2.8. ISO320. Spot metered on a specific patch of gray on the hat for consistent brightness. All shot with standard color JPEG all-zero settings straight from a LUMIX S1H camera. Shot on tripod with shutter delay. Focus was checked and double checked in live view before each shot was taken. If a slight field curvature in the focal plane is detected, I prioritize for the hat band and the dog. Only very minor tweak in exposure + convert to B&W in Lightroom. Text added in Photoshop. JPEG export quality set to max, sRGB, sharpen=0. Each image is a 3848x1785 center crop from a 6000x3368 image.


    To participate in the test, please view each test image in original size.


    Please reply with the following:


    1) Pick THREE images that possess the greatest / richest amount of micro contrast.


    2) Which area of the image is most revealing to you in micro contrast? Why?


    3) If you think this is an insufficient test of micro contrast, please explain.


    When we have a good number of responses, I will post the model of each lens used.



    I know this will inevitably spark some debate on this contentious topic. Please help keep this a civil and constructive experience. I believe our taste for good lens characters are after all, personal tastes. They are as psychological as they are physical. I hope this discussion will eventually help shed light on what our common denominators are when we define a good lens, and we may learn a thing or two from it.


    Jack Lam


    cinematographer


    www.Jack-Lam.com

    ------------------------


    Full composition (downsized, slate blurred out):
    [​IMG]


    Here are the test images:

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  2. Interesting. To my eyes, B and H are a little soft, but I couldn’t make any other rational comment about the others which all look equally good to me. It’s difficult trying to compare images when you can’t see them side by side, as you’re trying to remember whether image x has more ‘micro contrast’ than image y.

    I asked this question here a few years ago, And you are correct, it’s a contentious subject. To my mind, it’s not a thing. Is it recognised by lens manufacturers?
     
  3. People's reactions to optical phenomena may not be measurable, but optical phenomena are. Here's an explanation of the difference between microcontrast and resolution: https://luminous-landscape.com/understanding-lens-contrast/.
     
  4. I'm not sure about 'micro-contrast', I never heard the term till this posting. But for me, B clearly has a bit more contrast that the others and I like it best. For runner up, that's hard, but I'll say G. I also see that both B and G are rotated slightly more to the left than the other, but I don't think that influenced the contrast. Thanks for this posting.
     
  5. I've only heard the term with regards to film and edge sharpness, not lenses. I'd think MTF would tell you most of what you need to know about lenses.
     
    ed_farmer likes this.
  6. I scrolled these multiple times. None of them stand out in any remarkable way, but I like a and i best out of all of them- based on I'm not sure what.
    While I like the bokeh rendering of image/lens b, the image rendering itself wasn't a standout for me.
     
  7. WJT

    WJT Moderator

    I felt that A. B, and C were softer than the rest, especially B which was very soft in the fur hat. This softness does not look like a contrast issue but rather focus. I will have to take another look at the others.

    I think I like "I" the most as far as contrast/detail.
     
    Last edited: Jul 23, 2020
  8. I see the most contrast in G and I. With G having slightly more. I based this by first checking the focus of the hair on the left side of the hat rim of each image. Then looking at the contrast in the bond on the hat at the right edge and the contrast in the wood base for the dog carving. The wood base seems to show the most difference in contrast between the images.Whether this is correct to be termed "microcontrast" or just better resolution I am not sure.

    Microcont.jpg
     
  9. We're looking at digital images (and nothing else) on many different monitors, attempting to visually depict something that may or may not exist optically. .
     

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