Canon rf 10 20mm f 4l is stm vs sigma 10 18mm f 2 8 dc dn contemporary?

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From Sigma 10-18mm f/2.8 DC DN Contemporary: Sigma 10-18mm f/2.8 DC DN Contemporary: A zoom lens by Sigma for APS-C cameras, 10-18mm f/2.8. Specs - Maker: Sigma - Focal length: 10-18mm (zoom) - Maximum aperture: f/2.8 - Made for: APS-C sensors - Mounts: Sony E, Fujifilm X, L-Mount, Canon RF - Stabilised: no - Autofocus: yes What it frames like - On APS-C (Sony E, Fujifilm X, L-Mount): like 15-27mm on full frame; f/2.8 gives about the depth of field of f/4.2 there. ...

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 ...

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