Micro-contrast is often what is thought to give the "3D pop" to images but that's not all. They way a lens transitions from the in-focus areas to the out-of-focus areas also plays a huge role in that 3D look. Not to mention shorter focal lengths give less compression to an image. Historically, if you search for the best lenses for "3D Pop", you're likely to find fast lenses from Leica, Sony, Zeiss, Nikon, all around the 50-85mm range. How much of this is due to a narrow depth of field and a "normal" perspective, vs the lenses ability to produce micro-contrast?

Older uncorrected lenses with decent coatings tend to have better micro contrast because of their lower number of lens elements. I'm thinking of older lenses like Nikon's AIS 105mm f2.5 and 35mm f1.4.

Microcontrast refers to the level of contrast or sharpness in fine details within a photograph or image at a very small scale. It is often associated with the perception of fine textures, subtle variations in tone, and the overall clarity of small details. Microcontrast is distinct from global contrast, which refers to the overall difference in brightness between the light and dark areas of an image.

Photographers and image enthusiasts often pay attention to microcontrast because it can have a significant impact on the perceived sharpness and quality of an image. High microcontrast can make fine details stand out and give the image a sense of depth and three-dimensionality. Conversely, low microcontrast can make an image appear flat and lacking in fine detail.

Achieving good microcontrast in photography may involve using high-quality lenses, proper focus techniques, and post-processing adjustments. Some image editing software also includes tools for enhancing microcontrast, such as local contrast adjustments or sharpening techniques.

In summary, microcontrast refers to the level of contrast and sharpness in small-scale details within an image, and it plays a crucial role in the overall quality and perception of sharpness in a photograph or image.