Canon rf 800mm f 5 6l is usm vs canon rf 1200mm f 8l is usm?

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From Canon RF 800mm f/5.6L IS USM: Canon RF 800mm f/5.6L IS USM: A prime lens by Canon for Full frame cameras, 800mm f/5.6. Specs - Maker: Canon - Focal length: 800mm (prime) - Maximum aperture: f/5.6 - Made for: Full frame sensors - Mounts: Canon RF - Stabilised: yes - Autofocus: yes What it frames like - On full frame (Canon RF): as marked, 800mm. - On APS-C (Canon) (Canon RF): like 1280mm on full frame; f/5.6 gives about the depth of ...

From Canon RF 1200mm f/8L IS USM: Canon RF 1200mm f/8L IS USM: A prime lens by Canon for Full frame cameras, 1200mm f/8. The longest autofocus lens Canon makes. Specs - Maker: Canon - Focal length: 1200mm (prime) - Maximum aperture: f/8 - Made for: Full frame sensors - Mounts: Canon RF - Stabilised: yes - Autofocus: yes What it frames like - On full frame (Canon RF): as marked, 1200mm. - On APS-C (Canon) (Canon RF): like 1920mm on full frame; ...

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