Is the tokina f rin 20mm f 2 fe af sharp wide open?

Here is what the site says about that.

From Tokina FíRIN 20mm f/2 FE AF: Tokina FíRIN 20mm f/2 FE AF: A prime lens by Tokina for Full frame cameras, 20mm f/2. Specs - Maker: Tokina - Focal length: 20mm (prime) - Maximum aperture: f/2 - Made for: Full frame sensors - Mounts: Sony E - Stabilised: no - Autofocus: yes What it frames like - On full frame (Sony E): as marked, 20mm. - On APS-C (Sony E): like 30mm on full frame; f/2 gives about the depth of field ...

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.

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