Not to hijack this thread, but with reference to my post above, you can see differences in bokeh on the same camera with the same lens at the same aperture with the only difference being the strength of the backlight. It makes the lens look like two different ones.
In both shots, the camera was a D700, the lens a manual 2.8/135 Nikkor, hand-held, with the ISO at 400. Lens was wide open at f2.8 in both shots.
Probably also the subject being closer to the camera and possibly further away from the background helped with the second shot shown.