I've been moving my setup around trying to line up with a better background. It will be much easier once things start tuning green.
the exif is reporting 400mm at f5.6 but I taped the pins in the teleconverter to be able to use all the focus points. It works "ok" for a still subject but that's about all it can be used for. Still pretty helpful for framing.
1DIV 400 mm+1.4x
1/500 , f8
iso 1600
_DIV43351 by Stuart Edwards, on Flickr