another airshow question

[treeduck6]

The bag is not large enough to carry everything I want to bring - the 70-200 is packed but I need to choose between a 300 f4 and a 100-400 4.5-5.6 . Which would you bring? I am also packing a 1.4x & 2x extender. I think I loose autofocus with the 2x (have to check the book) so the 1.4x may be the only usable option.
I am not quite sure where I will be in relation to the show line so I am looking for the most useful combination of lenses.

Thanks

[theflyingkiwi]

If it was me, I would take the 100-400, It gives you the greatest of options when the action changes. that is the thing to think about, if you take the 300f4 even with the 1.4 attached you wont have the abilty to change zooms quickly (unless you own to cameras)

[chris.bailey]

100-400 every time and I would forget the 2x, its very hard to track a plane in the air with it.

[GyRob]

Im not a fan of zooms but the 100 to 400 would be your best bet.
ROB

[treeduck6]

looks like the 100-400 wins. Thanks very much.
I will search some of the old threads too but if anyone can offer any shooting tips i would appreciate it. It has been a little while since my last airshow and this will be my first with the 20d.
Thanks again.

[pcasciola]

Since you're brining the 70-200, I'd pick the 300/4L IS any day, and bring the 1.4x converter. I had the 300/4L IS and Sigma 500mm last week, and I found no need for less than 300mm at any point when I was there, so the zoom is not really needed.