I'm starting to explore various capture workflows for HD video at birds, and here's a couple of my first attempts using a production 5D2 - both using a manually focused 1600 mm (Sigmonster + 2x TC).
These are links to a 720p version (smaller size video is also selectable). 
1. Long-tailed Shrike
http://exposureroom.com/romyocon_longtailedshrike![]()
2. Common Moorhen
http://exposureroom.com/romyocon_moorhens![]()
Regards,
Romy

