Getting to 600mm

I've been using a 400mm f/5.6L as my primary birding lens for quite a while now and I find it a bit short for trying to photograph small birds such as nesting least terns, plovers, or shy birds that simply don't want me to get close. So I wanted to try out a TC on the lens. Has anyone had experience with this one?
http://www.adorama.com/LN15XKEOS.htm...24700691358224
I just can't pay the $$ for a 500mm or 600mm, there is no possible way that I could get the money for the summer season.Is the Canon TC a lot better than the Kenko? Any samples or suggestions on how to get to 500 or 600 is wanted.

Brian,

What camera model do you want to use the 400/TC combo with? The x0D cameras don't autofocus at F8 with which you will end up with by combining the 400F5.6 and a 1.4 TC. You'll loose one stop. The pro cameras still can autofocus at F8.

Solution with a x0D camera is to choose a non-reporting TC (e.g. from Tamron) or taping some pins on the Canon 1.4TC and others. Don't know about the Kenko you've linked.

I am using the (cheap) Tamron 1.4TC but have to say that the AF accuracy and speed dramatically declines in my experience making BIF or any dynamic scenery very very difficult to impossible. Others don't report such difficulties. YMMV.

Good luck! JR

A non-reporting TC is probably your only choice. The image quality will degrade and the AF performance (oscillation) won't be good either, when used on a xxD or xxxD body. On a 1D body the quality and AF performance are acceptable.

I forgot to mention that I am using a 1D2.

I believe you'll get AF at f/8. That being the case, I would go with the Canon 1.4x. You'll get the best image quality by far.

I used a Canon 1.4x TC on my 1D3 together with the 400f/5.6 once, the results were quite good and the AF performance was not bad either.

I have a kenko 1.4x and the autofocus works with the pins taped. I've been pretty happy with the image quality but it's not a low light combination.