Quote Originally Posted by nvitalephotography
So i guess it comes down to which of these is more important to have, a faster lens or a longer focal length for things like candid shots.

Another vital factor is wide angle. The 24-105 doesn't give you an option to take any wide angle shots. Plus autofocus -- the f/2.8 will allow you to use the high precision f/2.8 autofocus sensor, which is six times more accurate than the ones that the 24-105 f/4 will let you use.


Personally, I'd go for the 17-55 (I mostly shoot weddings with primes).