Canon 550D for HD video? (Zoom & Focus?)?

-I am looking at getting a 550D for HD video but cant work out how i would use the manual zoom or focus while filming?!? Manually, i know. But that would be rubbish and jerky?well now you know the primary difference between a digital still camera lens and a camcorder. with a still camera, you set the zoom position, focus, adjust exposure before you press the shutter. the lens is not built to make changes while shooting like a camcorder does. so it sounds like a camcorder may be more satisfactory for your style of shooting video.