Is the canon rf 1200mm f 8l is usm long enough for birds?

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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; ...

From Wildlife and sport: Reach: Focal length is the first thing to sort out. - Sport from the sideline and larger animals: 70-200mm to 100-400mm on full frame. - Birds: 600mm full-frame equivalent and beyond. Birds are small and far away; a common saying is that you never have enough reach for them. Smaller sensors help here. A 100-400mm lens on APS-C gives the view of about 150-600mm on full frame, and on Micro Four ...

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