Zoom lenses

Zoom lenses are more complicated by construction and mostly inferior by photohraphy quality compared to fixed objectives. However, their usableness and flexibility greatly outstrips small compromise considering quality. Also they exist in wide and tele area and there are those that strech from wide to tele area. The quality is mostly higher as the zoom factor is smaller because less compromise is needed compared to high zoom factor objectives. Usual ranges are 17-40mm, 24-70mm, 70-200mm, 100-400mm.