Invertalon wrote in post #16591119
I should say the Canon 17-40 and 16-35 are your best options.
Both have similar performance, but the 17-40L is lighter but only f/4, which is perfectly fine for landscape since you will be stopping down anyway. The 16-35 is a little more hefty but performs very well wide open at f/2.8. The 16-35 is double the price, though.
On a 6D, you ideally would want a 16-17mm wide end for some great perspective.
I would recommend the 17-40L though in your case, and maybe pick up a Samyang 14mm for those times you really want extreme wideness. Both can be had for less than the 16-35 by itself (the Mark II).
Canon's wide angle glass is kinda ~meh. The 16-35mm is uber-$$$ and is better than the original version - e.g. - condemned by faint praise. it's also an isometric workout and anything but inconspicuous.
I spent 8 hours last week testing my new 100mm L on a crop body at a local botanical gardens (great lens). As an after-thought, I mounted the lowly 35mm f/2 (non-IS) on my de-gripped 5D as a second body/perspective (thus avoiding most lens changes - although we did carry the 10-22mm uwa).
The point, to this anecdote, is that days later, the 300+ images from the 35mm stole the show. Mostly SooC, they are simply stunning. And from an inexpensive lens - that's cheap, unobtrusive, short, light - - - what's not to like?
Nothing against red-ringed lenses (see comment re 100mm L above), but good images are good images. Regardless.