Thanks, I cant afford the 100-400 yet but Im finding the 70-200 F4 non IS with a 1X4 TC very good. Would love a little more reach though
If you just need a little more reach every so often, my experience is that the 2X extender will do nicely, even though it is MF only on a crop body. I shot some nice pictures with the 70-200 F/4 L non-IS and 2X extender combo at the Open National Glider Aerobatics Championships last year. I really needed the reach, because of the size of the air field, and the movement restrictions because the event was staged on a military air field. Fortunately, light wasn't the problem at the time.
However, this was a very good reason for me to acquire the 100-400
.
HTH, kind regards, Wim



