The segment of ultra-wide, fast zoom lenses designed for full frame is very differentiated. In fact it seems every producer follows their own path, or even several paths at the same time. In the case of Canon it all started in 1989 with the EF 20–35 mm...

I bought this lens to replace my Canon 16-35 f/2.8L II. It is sharp. Very sharp. It's sharper in the corners than the Canon is in the center. However, it has ridiculously bad purple fringing to the point where it almost becomes a purple haze if you are...