Sigma 15mm f 1 4 dg dn diagonal fisheye art vs sony fe 16mm f 1 8 g?

Here is what the site says about that.

From Sigma 15mm f/1.4 DG DN Diagonal Fisheye Art: Sigma 15mm f/1.4 DG DN Diagonal Fisheye Art: A prime lens by Sigma for Full frame cameras, 15mm f/1.4. A fast full-frame fisheye, made with night-sky photography in mind. Specs - Maker: Sigma - Focal length: 15mm (prime) - Maximum aperture: f/1.4 - Made for: Full frame sensors - Mounts: Sony E, L-Mount - Stabilised: no - Autofocus: yes What it frames like - On full frame (Sony E, L-Mount): as marked, 15mm. - On APS-C (Sony E, ...

From Sony FE 16mm f/1.8 G: Sony FE 16mm f/1.8 G: A prime lens by Sony for Full frame cameras, 16mm f/1.8. A small, fast ultra-wide prime that takes ordinary screw-in filters. Specs - Maker: Sony - Focal length: 16mm (prime) - Maximum aperture: f/1.8 - Made for: Full frame sensors - Mounts: Sony E - Stabilised: no - Autofocus: yes What it frames like - On full frame (Sony E): as marked, 16mm. - On APS-C (Sony E): like 24mm ...

Quoted from this site's pages.