How to judge the quality of a shot? It's urgent and needs to be objective, about 100 words.

There are many measures of lens, the most important ones are MTF, modulus transfer function and high MTF score, which shows that the radial and tangential distortion in the center and around the lens is small. Generally, this index of zoom lens cannot exceed that of fixed focus lens. So professional photography must use fixed focus to shoot. For specific data, please refer to the strongest 19 lens in the history evaluated by Hasselblad Lab, with Leica and Zeiss each accounting for half.

As for the "low dispersion lens" and "aspheric glass" of zoom lens, they can be ignored. This material is used for zoom lens, not to obtain high imaging, but to reduce serious distortion and dispersion under large zoom, so that the effect is basically acceptable. As for a brand, labeling it "APO" is basically a joke. The word apo is equivalent to nobility in the field of lens, and not all lenses can be labeled. Even if some Japanese brands are marked with APO, the effect is at most half that of Zeiss without APO.