A wide-angle lens is a lens that has a focal length that is shorter than that of the normal lens .
By definition , wide-angle lenses differ from ultra wide angle lenses in that the latter have a focal length shorter than the short side of the film or sensor , which means that in 35mm , a wide-angle lens has a focal length between 35 and 24 mm , while an ultra wide-angle lens has a focal length shorter than 24 mm .