I have used the 70-200mm f/4 with 1.4X, 2X, and both stacked with good results. However, its not at all user friendly to add and take off the extenders in the field.


70-200mm F/4L IS with Canon TC 1.4X II


[View:http://www.mount-spokane-photography.com/Nature/Birds/Finchesextender-test/814931712_37iMo-X2.jpg]:800:800]


70-200mm F/4L IS with Canon TC 2X II


[View:http://www.mount-spokane-photography.com/Nature/Birds/Finchesextender-test/814983596_HQMaY-X2.jpg]


70-200mm F/4L IS with Canon TC's 1.4X II and 2XII stacked. My <span style="text-decoration: line-through;"]5 1D MK III does autofocus if I get it close manually.


[View:http://www.mount-spokane-photography.com/Nature/Birds/Finchesextender-test-2X/814933088_ZNnYJ-X2-1.jpg]