One thing that all Zoom lenses have in common is the need to move groups of elements axially in a very precise but independent manner. It is not uncommon for lens groups to reverse direction of motion while continuing to zoom to a longer focal length. This requires excellent control over the optomechanical tolerances of the system.
SMA Optical Technologies has experience in dealing with these issues.
The Zoom lens is a class of lens that has become ubiquitous in our world. We find them in imaging devices ranging from cell phones to high end broadcast quality video cameras. Once constrained solely to spherical glass elements, today's lenses utilize molded glass aspheric elements, aspheric molded plastic elements, and sometimes even diffractive elements.