I have the 17-40 / 4.0 L lens. The Dremel lens hood is made for Vollfomat sensor. This it is very narrow and shadowed little off. I have a 1.6x crop camera (350D) and ordered this lens hood for my lens. They are significantly more shadowing and is still not visible in the pictures. So no black borders, even at 17 mm focal length. Too bad that you can select the lens hood is not depending on the sensor size when ordering the lens. Inside flocked and is tight as it should be.