Useful wide standard
This is an excellent lens given it's relatively wide range and f4 maximum aperture. Two fairly minor issues keep it from a 5 star rating in my opinion. Significant vignetting when wide open and the IS, while very useful isn't up to what the newest generation lenses are offering. The build quality is worthy of it's 'L', as is the zooming action. It's not a lightweight, but that only reflects it's a serious quality lens IMO. It takes 77mm filters, good if you already own some and use say the 70-200 f2.8. I would strongly recommend this lens for aspiring landscape or portrait or wedding photographers. If I were to replace it I'd opt for the new 24-70 f2.8L II despite it's not having IS and isn't as flexible focal length wise. Still an excellent and very useful pro level lens.