What is the function of Canon 70200 f4 Guo Xuwei? Is it effective to take portraits?

L-class telephoto zoom lens has excellent portability. Among Canon 70-200mm series lenses, the lens body is the smallest and lightest, with outstanding cost performance. The basic structure of the lens is basically the same as that of EF 70-——200mm f/4L is USM, and the difference between them lies in whether it is equipped with hand shake compensation mechanism. On the basis of cost control, fluorite lens which can effectively remove residual chromatic aberration is still used, and high image quality can be obtained with UD (ultra-low dispersion) lens. The nearest focal length is about 1.2 m, and the telephoto end of 200mm can obtain the telephoto macro effect. It has high definition and contrast, and the definition is outstanding. Appropriate lens aperture reduces the occurrence of spherical aberration and can be used safely under the maximum aperture. Appropriate zoom ratio ensures the stability of image quality in the whole zoom range, and good results can be obtained at any focal length, thus making photographers feel highly satisfied. The diameter of the filter is about 67 mm, and the mirror body is slender, so it can be put into a medium-sized camera bag, or it can be put into a big pocket or a shooting pocket of a shooting suit. It is a zoom lens with high portability, image quality and cost performance.

Guo Xuwei is zoom, and 50mm is fixed focus. I don't know which 50mm you are talking about, so there is no comparability at all.