Sigma 120 300mm f 2 8 dg os hsm sports vs canon ef 75 300mm f 4 5 6 iii?

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From Sigma 120-300mm f/2.8 DG OS HSM Sports: Sigma 120-300mm f/2.8 DG OS HSM Sports: A zoom lens by Sigma for Full frame cameras, 120-300mm f/2.8. A constant f/2.8 telephoto zoom for sport, big and heavy. Specs - Maker: Sigma - Focal length: 120-300mm (zoom) - Maximum aperture: f/2.8 - Made for: Full frame sensors - Mounts: Canon EF, Nikon F - Stabilised: yes - Autofocus: yes What it frames like - On full frame (Canon EF, Nikon F): as marked, 120-300mm. - On APS-C ...

From Canon EF 75-300mm f/4-5.6 III: Canon EF 75-300mm f/4-5.6 III: A zoom lens by Canon for Full frame cameras, 75-300mm f/4-5.6. A very common cheap telephoto: soft at 300mm and not stabilised. Specs - Maker: Canon - Focal length: 75-300mm (zoom) - Maximum aperture: f/4-5.6 (it gets darker as you zoom in) - Made for: Full frame sensors - Mounts: Canon EF - Stabilised: no - Autofocus: yes What it frames like - On full frame (Canon EF): as marked, ...

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