How sharp is the canon rf 10 20mm f 4l is stm?

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From Canon RF 10-20mm f/4L IS STM: Canon RF 10-20mm f/4L IS STM: A zoom lens by Canon for Full frame cameras, 10-20mm f/4. Specs - Maker: Canon - Focal length: 10-20mm (zoom) - Maximum aperture: f/4 - Made for: Full frame sensors - Mounts: Canon RF - Stabilised: yes - Autofocus: yes What it frames like - On full frame (Canon RF): as marked, 10-20mm. - On APS-C (Canon) (Canon RF): like 16-32mm on full frame; f/4 gives about the depth of ...

From Portraits: The camera: What matters most is eye autofocus, which current mirrorless cameras do very well: it finds the nearest eye and tracks it, so wide apertures stay sharp. Full frame gives you more background blur at the same f-number than APS-C, but a fast APS-C lens closes most of that gap for far less money; see sensor sizes.

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