Female Chaffinch

This photo was taken in my garden during March 2009.
The technical information is as follows.
Camera - Canon EOS 50D
Shutter speed - 1/320
Aperture - f8.0
Lens - Canon EF 400mm f5.6 L USM plus Kenko 36mm Extension Tube
Focal Length 400mm
ISO 400
Tripod