Canon ef 16 35mm f 4l is usm vs sigma 12 24mm f 4 dg hsm art?

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From Canon EF 16-35mm f/4L IS USM: Canon EF 16-35mm f/4L IS USM: A zoom lens by Canon for Full frame cameras, 16-35mm f/4. Specs - Maker: Canon - Focal length: 16-35mm (zoom) - Maximum aperture: f/4 - Made for: Full frame sensors - Mounts: Canon EF - Stabilised: yes - Autofocus: yes What it frames like - On full frame (Canon EF): as marked, 16-35mm. - On APS-C (Canon) (Canon EF): like 26-56mm on full frame; f/4 gives about the depth of ...

From Sigma 12-24mm f/4 DG HSM Art: Sigma 12-24mm f/4 DG HSM Art: A zoom lens by Sigma for Full frame cameras, 12-24mm f/4. Specs - Maker: Sigma - Focal length: 12-24mm (zoom) - Maximum aperture: f/4 - Made for: Full frame sensors - Mounts: Canon EF, Nikon F - Stabilised: no - Autofocus: yes What it frames like - On full frame (Canon EF, Nikon F): as marked, 12-24mm. - On APS-C (Nikon F): like 18-36mm on full frame; f/4 gives about ...

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