p.6 #1 · Focal Length Compression vs. Microcontrast
Todd Adamson wrote:
Why does the Zeiss 100/2 image look more 3D, and the Nikkor 135/2 image look flat and cardboard cutout-ish by comparison? Is it entirely due to the Zeiss' "3D" rendering capability, said to be from its superior microcontrast, and CA control? Or is it simply due to the difference in focal length? I have a feeling it's a combination of the two, but which is more important?
All images are 2D in nature. The 3D is a perception formed in our brain by combining all sorts of visual cues. In the samples you provided (human face), the 3D feel is mostly due to shading (the gradual change of color due to surface curvature) & texture (to a lesser degree). The focal length compression is a much smaller factor. Why? The moon surface gives us unmistakable 3D feel even under high powered telescope (big FL compression effect), because the main visual cue is shading.
So, whichever lens renders more dynamic shading, preserves more texture, will give us better 3D feel. Similarly, with the same lens, a camera with better dynamic range will give us better 3D feel too.
My guess is #2 and #4 are by the same lens.
Todd Adamson wrote:
So, are they really different, and if so, why?
IMO, it's determined by the lenses design, the optical fomula. The difference in the PSF (point spread function) of a lens would have quite a big impact in how shading and texture are rendered. It's possible that a Nikon lens is better in this regard than a Zeiss, different lens (regardless of brand) will behave slight differently.
