Nice work and not all that oversharpened...what radius did you use? I assume this is a 100% crop? How much better is the Kenko 2x TC, than the Canon series ii 2x TC?
Carl - Glad you (and rpt) liked the shot.
For info: f11 1/25th at iso 320
Adobe Camera RAW:
(Basically mess around with the sliders 'til it looks okay(!) and also tweak the curves and contrast etc.)
The cropped image ended up 2512*1905 then was resized for posting here.
As for the Canon 2x mk2 TC. No idea! I've had the Kenko 1.4x and 2x DG 300 TCs for a while now. I originally got them for use with my 300mm f2.8 IS mk1. The 1.4x is very good, very sharp but the 2x is pretty soft so I only use it if absolutely necessary. I got the Canon 1.4x mk3 TC free when I bought the 500mm. I haven't compared the Kenko 1.4x to the Canon with regards to speed - I just assume (hope!) the Canon provides faster focussing as it's designed specifically for the mk2 big whites.
Both Kenko TCs aren't worth much secondhand so I'll probably keep them for use with my Tamron 90mm macro. Clearly Canon have a reason for designing their TCs the way they do but the protruding front element really screws up your choices of what lenses you can use with them.