In fact the most versatile lens for video is a zoom 17-50 F2.8 constant. The Tamrom is good for video. Strangely the Tamron VC version has less sharpness, but nothing is visible on video. The Sigma 17-50 F2.8 OS, seems the best option to take pictures too, because the sharpness is better. If you get more serious video, prime lenses are great a option. For example, a set of Samyang 14mm F2.8 + 35mm F1.4 + 85mm F1.4 caters well various situations, but the focus is manual only, as the Cinema traditional.