I have this goal for two months. The optical quality is on a Canon 20D époustoufflante. For a reasonable price, you have a goal 'white', very pro series L. The aperture of f / 4 makes it a less expensive lens, but also lighter than the f / 2.8. Mounted on the housing, it has a good grip. The ZOOM and FOCUS rings are wide and comfortable. You have the option of manual editing and two distance intervals. Supplied with a lens hood and a soft case.