Thanks for the reply. Yes the 200 f2.8 w/ the 2x is great & have used it handheld many times w/ great success. The 2x also works great w/ 70-200 f2.8.
I did not know that you could stack them either but read George Lepp's column in this month's Outdoor Photo & was shocked that he uses the stack set w/ f4 500. Must go w/ manual focus which makes sense but he does not say that.
Have always used full frame ever since the 5D came out. Now have 5D III. B4 that only slides. Too cheap to go w/ 1D.
Have always used 2x w/ the 300 f 2.8, since 2003. The 300 w/ 2x combo is great but need more reach, especially w/ birds. Unfortunately you can't find any 400 f 2.8 for a reasonable cost & new ones are out of sight.
Your point is well taken though. Have used my 200-400 w/ the 2x but it is marginal, the auto focus only works at center & the viewfinder is very dim. Would be hard to do effective manual focus, except on a preset distance & f 8 - 11.
Thought I would look into it however, especially since Lepp seems to indicate that he uses the combo on a frequent basis.
