Photo taken in Carlisle -Lady was in Penrith!

He he, joking I am.I was having a wee test of the Canon 100mm-400mm f4.5-f5.6 L IS.



My dillemma is as follows

I have the 70mm-200mm f4 L non IS
I want to reach 400mm

with up to £1500 to spend I can only get f5.6 at 400mm
if I buy the zoom I tried today (£1250) I get the reach, the IS and the aperture

but

if I buy a Canon x2 teleconverter plus 70-200 f2.8 L (non IS) (total cost about £1450) I get the same reach and aperture but not the IS - but crucially, when used without the x2 telecon' I will get double the speed I currently enjoy from my f4 and could potentially sell the f4 for at least the extra cost of buying these two over the one zoom.

So I need to know -

how much poorer will my results be at 400 through the x2 telecon' compared to at 400 on the 100-400

Will I struggle to get sharp enough shots at 400mm without IS?

will the x2 telecon make my 5D2 struggle to AF compared with the zoom (which seemed to work as well as I am used to)

Next week I will be able to test the x2 so should get more of an idea whats what but in the interim Id be pleased to hear any Blippers thoughts