This NiSi 58mm Close-Up Lens Kit offers the ability to achieve macro-like results with camera lenses that feature focal lengths from 35 to 250mm and have 58, 52, or 49mm front filter threads. A close-up lens is a magnifier that optically decreases the focal length of a camera lens placed behind it. This effect lessens the minimum focus distance between the camera lens and a subject. Magnification can then be obtained by decreasing the distance between the subject and the combined camera lens and close-up lens. On lenses with or set to a 120mm focal length, this close-up lens provides an approximate 1:1 magnification.