Is the ttartisan 21mm f 1 5 asph sharp wide open?

Here is what the site says about that.

From TTArtisan 21mm f/1.5 ASPH: TTArtisan 21mm f/1.5 ASPH: A prime lens by TTArtisan for Full frame cameras, 21mm f/1.5. Specs - Maker: TTArtisan - Focal length: 21mm (prime) - Maximum aperture: f/1.5 - Made for: Full frame sensors - Mounts: Sony E, Nikon Z, Canon RF, Leica M - Stabilised: no - Autofocus: no, manual focus What it frames like - On full frame (Sony E, Nikon Z, Canon RF, Leica M): as marked, 21mm. - On APS-C ...

From Leica Tri-Elmar-M 16-18-21mm f/4 ASPH: Leica Tri-Elmar-M 16-18-21mm f/4 ASPH: A zoom lens by Leica for Full frame cameras, 16-21mm f/4. Three ultra-wide focal lengths in one lens.

Quoted from this site's pages.