At f3.5 80% of the shots are blurry anyway, I don't even know why they made it possible to chose that aperture
I was always at f6.3 @ Geneva last week and it wasn't that bad :bah: As I said, if you know how the lens will react it's easier, I only set one focusing point and did the job myself.
If you really want a lense which covers this range then you have to look for an EF-S 17-85 IS USM (but the distortion and AC are high at 17mm) or (TT close your eyes) a Sigma 18-50 f2.8 (not talking about the new Canon 17-55 f2.8 IS USM which is pointless IMO)
The first one is wayyy to expensive (the price of a 70-300 IS) but the second one could be okay, dunno the real price though.
Nth, you should replace that old f4.5-5.6 100-400 by an f2.8L IS USM and that's nearly the perfect config, the only thing is that you first have to sell a few organs before having the money because an EOS 1Ds mkII should be even better than this cheap 350D
