What is the difference between Canon's 17-40 and 16-35 except the price of aperture focal length?

I've used both of these shots, but I haven't carefully evaluated them together. I can only talk about my experience.

1740, imaging is not as criticized by some people. Actually, this head has a good image. If it is not good, it may be out of focus. This will happen. 17 has defocus. I don't know if it is an individual problem. When I use the wide-angle end, I always focus on the 40 end and shoot when I zoom to the 17 end. In addition, this head is bright in color, but slightly dry, and the scenery is still very good.

1635 is a very balanced lens. The corner resolution is very good, and the color reproduction is more realistic and moist, which is different from the style of 1740. Landscape photography and environmental portrait photography are both suitable.