Is the sony fe 400 800mm f 6 3 8 g oss long enough for birds?

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From Sony FE 400-800mm f/6.3-8 G OSS: Sony FE 400-800mm f/6.3-8 G OSS: A zoom lens by Sony for Full frame cameras, 400-800mm f/6.3-8. Sony's longest zoom, for birds and distant wildlife. Specs - Maker: Sony - Focal length: 400-800mm (zoom) - Maximum aperture: f/6.3-8 (it gets darker as you zoom in) - Made for: Full frame sensors - Mounts: Sony E - Stabilised: yes - Autofocus: yes What it frames like - On full frame (Sony E): as marked, 400-800mm. - On ...

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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