How sharp is the canon rf s 7 8mm f 4 stm dual?

Here is what the site says about that.

From Canon RF-S 7.8mm f/4 STM Dual: Canon RF-S 7.8mm f/4 STM Dual: A prime lens by Canon for APS-C cameras, 7.8mm f/4. A twin lens for recording spatial video, made for the R7. Specs - Maker: Canon - Focal length: 7.8mm (prime) - Maximum aperture: f/4 - Made for: APS-C sensors - Mounts: Canon RF - Stabilised: no - Autofocus: yes What it frames like - On APS-C (Canon) (Canon RF): like 12mm on full frame; f/4 gives about the depth of ...

From Portraits: Aperture and background blur: A wide aperture (a small f-number like f/1.8) gives a shallow depth of field: sharp eyes, soft background. Blur also grows with focal length, with getting closer to your subject, and with putting more distance between the subject and the background. Moving your subject away from a wall often does more than a faster lens. At f/1.4 and wider, the depth of field can be thinner than a face. Stop ...

Quoted from this site's pages.