Definitions for "Telephoto lens"
a special compound camera lens with a long effective focal length but used in a camera with a short focal length, allowing large images to be obtained of distant objects when used in a camera in place of an ordinary lens; -- called also telephotographic lens.
A multi-component lens arranged so that the overall length of the compound system is less than or equal to the effective focal length.
A lens that magnifies an image and produces a narrowed angle of view. As the focal length increases, the magnification increases and the angle of view decreases.
a prerequisite for a frame-filling image of a moose
a must, to catch any of a tremendous variety of birds in flight
Keywords:  far, extremely, objects, close, ups
Used for close-ups of objects that are extremely far away.
Keywords:  necessary, equipment, piece
a necessary piece of equipment