Is the nikon z 20mm f 1 8 s sharp wide open?

Here is what the site says about that.

From Nikon Z 20mm f/1.8 S: Nikon Z 20mm f/1.8 S: A prime lens by Nikon for Full frame cameras, 20mm f/1.8. A fast wide prime, popular for landscapes and night skies. Specs - Maker: Nikon - Focal length: 20mm (prime) - Maximum aperture: f/1.8 - Made for: Full frame sensors - Mounts: Nikon Z - Stabilised: no - Autofocus: yes What it frames like - On full frame (Nikon Z): as marked, 20mm. - On APS-C (Nikon Z): like 30mm ...

From Lenses: Aperture: The f-number says how wide the lens opens. Smaller numbers let in more light: f/1.8 lets in about ten times as much light as f/5.6, more than three stops. A wide aperture means faster shutter speeds in dim light and more background blur. Zooms with a constant aperture, like a 24-70mm f/2.8, keep the same exposure throughout the zoom range; cheaper zooms get darker as you zoom in.

Quoted from this site's pages.