What are the key differences between the Canon 16-35 and 17-40 lenses, and which one would be the better choice for landscape photography?

The key differences between the Canon 16-35 and 17-40 lenses are their focal lengths and maximum apertures. The 16-35mm lens has a wider focal length range and a larger maximum aperture, making it better for low light situations and achieving a shallower depth of field. The 17-40mm lens is more affordable and lighter, making it a good choice for landscape Photography where weight and cost are important factors. Ultimately, the better choice for landscape photography would depend on your specific needs and preferences.