Jan 23, 2021 · Just like its 24mm f/1.8 S brother, the Nikon Z 20mm f/1.8 S is noticeably longer than the F-mount 20mm f/1.8G lens. However, it is shorter and almost twice lighter compared to the Sigma 20mm f/1.4 Art. Another advantage is that you don’t have to use the FTZ adapter, which only adds more weight and bulk to the setup.