Sigma 500mm f 4 dg os hsm sports vs nikon af s 500mm f 5 6e pf ed vr?

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From Nikon AF-S 500mm f/5.6E PF ED VR: Nikon AF-S 500mm f/5.6E PF ED VR: A prime lens by Nikon for Full frame cameras, 500mm f/5.6. A hand-holdable 500mm prime for wildlife. Specs - Maker: Nikon - Focal length: 500mm (prime) - Maximum aperture: f/5.6 - Made for: Full frame sensors - Mounts: Nikon F - Stabilised: yes - Autofocus: yes What it frames like - On full frame (Nikon F): as marked, 500mm. - On APS-C (Nikon F): like 750mm on full frame; f/5.6 ...

From Sigma 500mm f/4 DG OS HSM Sports: Sigma 500mm f/4 DG OS HSM Sports: A prime lens by Sigma for Full frame cameras, 500mm f/4. Specs - Maker: Sigma - Focal length: 500mm (prime) - Maximum aperture: f/4 - 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, 500mm. - On APS-C (Nikon F): like 750mm on full frame; f/4 gives about ...

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