I have recently acquired a Canon 7d body and matched it with a Canon 17-55 f/2.8 as my main on camera walk-around lens. At the same time I also purchased the Canon 70 - 300 f/4.5 - 5.6 lens.
I am now thinking of replacing & upgrading the 70 - 300 to an L series lens, but with a somewhat limited budget I am not sure which L series lens to get.
I regularly find myself shooting at the extreme focal length of my existing 70 -300 lens, (and at times wishing I had more focal length) so based on this fact, I am sort of leaning towards the Canon 100 - 400 f/4.5 - 5.6 L. On the other hand, I would like a lens with an aperture of f/2.8, but the only lens with a fixed aperture of 2.8 in my budget is the 70 - 200 f/2.8 L.
Do I trade off focal length for aperture or do I trade aperture for focal length?
The lens will mostly be used for sports and holidays (going to China soon, then Hawaii & then Africa so it will get plenty of use).
