The difference between Leica S series and M series cameras is the sense of body.

The biggest difference is the different structure. Leica M is a paraxial structure, so the lenses are mostly symmetrical and small in size. Because of the short flange distance of the paraxial structure, M series has great advantages in wide-angle lens.

Leica S is a SLR structure, and the flange distance is much longer than that of the paraxial structure. Therefore, SLR lenses are usually designed with various telephoto-proof mechanisms, and the lens volume is large, but the advantage is the medium telephoto lens.

In addition, Leica M-series camera has a frame of 135 Quan Huafu, while Leica S has a frame of 120. Although it is not Quan Huafu 120, the actual frame area is much larger than M series. Because of the different frame sizes, the focal length parameters of the two lenses are also different. For example, the standard lens in the 135 frame is 50MM, but in the 120 frame, the same lens as the 50MM lens in the 135 frame should be 80MM, and the imaging range of the 50MM lens in the 120 frame is approximately equal to 65430.