For some time now I've been eyeing canon's 35 1.4 L. However, I have a good 16-35 2.8 L already. I'm wondering if anyone in the forum might own both of these lenses and let me know their opinions of the value of owning both? I don't need the extra light necessarily. Part of my wondering is that a review of my portfolio would quickly show that I take a lot of zoomed in photos of people (for travel photography), but have been taking few of people within the context of their environment. I'd really like to improve in this area, and am wondering if their might be added benefit the 35 1.4 L would offer me over the 16-35 2.8 L. Maybe I'm just turning into a lens junkie!
At 35mm, in the center of the frame, at f/2.8, the 35L is the sharper lens, by a small but clearly visible amount when viewed at 100%. In the corners, the 35L is a bit soft, but much better than the zoom.
At f/8, in the center of the frame, the images are identical to my eye at 100%. But in the corners, the 35L still has the advantage, since it's virtually as sharp in the corners as it is in the center, and the zoom is still noticeably softer in the corners than in the center at f/8.
I'm very happy with the performance of the zoom. But let's face it. The 35L is one of the best lenses I've ever used, and I'm very happy with my M Summicrons. The 16-35L is one of the better zooms available, in my opinion. But it can't compete with the 35L, except stopped down in the middle.
I'm making the comparison on a 5D. If you want the best image quality possible, get the 35L. I just doesn't have any weaknesses that I can find, though my wallet's feeling a bit limp these days. I got it last month.