Review on Ultra Wide Angle Zoom Lens for SLR Cameras - Canon EF 17-40mm f/4L USM by Doyun Pak ᠌

Excellent lens for shooting from a tripod at a small aperture You don't need to demand anything else from him. Compared to 16-35, light and compact, you can carry it with you everywhere. It loses in aperture ratio, on a closed aperture, the pictures cannot be distinguished. Pros: At full frame, I use the main travel zoom in the mountains and in cities The picture is excellent at 8 f-stops. Cons below: Vignetting - removed in Lightroom Poor picture wide open - a lens for leisurely shooting