I would like to ask about the four different structures of Zeiss lenses. .

First of all, distagon cannot be compared with the other three. It is a wide-angle structure, and the other three are header or medium focus. In the existing lens system, distagon is mainly 28 and 35, and 18 is also useful. But those below 28 are mainly dominated by biogon (hologon exists as a legend). It doesn’t make much sense to discuss the suburbs with the light-angle head. After all, it is rarely tried at full open. The edges of this structure are a bit scattered, and there are no characteristics in the suburbs. Some heads are slightly bilinear.

Tessar’s simple header has been eliminated by Zeiss in the professional photography lens market, but there are still a large number of manufacturers that imitate it to produce low-end lenses. This head is prone to coma aberration and the bilinearity is more obvious than other structures, making it difficult to create a large aperture.

Planar currently has one of the best lens structures. It is suitable for manufacturing large aperture lenses and medium focal lengths. It is difficult to find a lens that can exceed its level in terms of out-of-focus performance (the basic difference lies in individual differences and different manufacturers). (Differences in workmanship brought about by the difference in workmanship), the legendary melting of butter when cut with a hot knife begins with the description of planar. When it comes to aperture blade quality, the out-of-focus spot is the best of almost any lens. (That is, the best combination of coma aberration, chromatic aberration and bokeh)

Sonnar has a large aperture and medium telephoto structure. Except that chromatic aberration may cause purple or green edges, there is nothing to say. The mid-length toe is the most classic structure. First, the blur effect is the best among the above heads (there are factors affecting the focal length).

lz is right to play with structure, but the choice of focal length must take priority.