Sigma 20mm f 1 4 dg dn art vs ttartisan 21mm f 1 5 asph?

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From Sigma 20mm f/1.4 DG DN Art: Sigma 20mm f/1.4 DG DN Art: A prime lens by Sigma for Full frame cameras, 20mm f/1.4. Specs - Maker: Sigma - Focal length: 20mm (prime) - Maximum aperture: f/1.4 - Made for: Full frame sensors - Mounts: Sony E, L-Mount - Stabilised: no - Autofocus: yes What it frames like - On full frame (Sony E, L-Mount): as marked, 20mm. - On APS-C (Sony E, L-Mount): like 30mm on full frame; f/1.4 gives about the ...

From TTArtisan 21mm f/1.5 ASPH: TTArtisan 21mm f/1.5 ASPH: A prime lens by TTArtisan for Full frame cameras, 21mm f/1.5. Specs - Maker: TTArtisan - Focal length: 21mm (prime) - Maximum aperture: f/1.5 - Made for: Full frame sensors - Mounts: Sony E, Nikon Z, Canon RF, Leica M - Stabilised: no - Autofocus: no, manual focus What it frames like - On full frame (Sony E, Nikon Z, Canon RF, Leica M): as marked, 21mm. - On APS-C ...

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