Hi Guys,
I am looking for a sports lense BESIDES the 70-200 f/2.8 IS (As i plan to get this later on).
I will mainly be using it to photograph surfing so i need a bit of reach if i am going to be on a beach. I have been looking at the 100-400L and the sigma 50-500 and 150-500.
I've read that sigmas AF's are slow but i haven't really found much out about the 100-400L. It looks like a great lense with its aperture and reach as well the IS being the main priority why i am looking at it and it is only a couple of hundred more expensive than the sigmas, but i have not used a sigma and was wondering on an opinion between the differences e.g. sharpness, WHY you chose which lense/what lense did you choose etc... I will use this also to photograph wildlife later down the track if it is useful. I do not care about weight as i can deal with that and don't care how heavy a lense is, if it gets me the reach and the picture i want 
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I have a 400D and a 50D as well, i will most likely be using the 50D if this makes any difference.
Many thanks!
