Apochromatic correction and the use of a lens element with an aspherical surface are combined in this compact telephoto lens for high-performance imaging. Two of the five lens elements are made of high-refraction optical glass. Two other lens elements have anomalous partial dispersion. As a result, brilliance and resolution are exemplary, even at full aperture. Peak performance is achieved at full aperture. Vignetting is already minimal with the lens wide open. As a result of the large aperture of f/2 and impressive
contrast rendition, it produces a particularly bright viewfinder image that permits very accurate and positive focusing, even in poor light. The nearest focusing distance is 0.7 m (27.5 in), so that subjects as small as 14 x 21 cm (5.5 x 8.25 in) can be explored. Combining this lens with the LEICA APO-EXTENDER-R 2 x produces a high-performance tele combination of 180 mm f/4.