The LEICA VARIO-ELMAR-R f/3.5-4/21-35 mm ASPH. is a compact and light-weight addition to the zoom lenses in the Leica R SLR system of Leica Camera AG, Solms, covering the four most frequently used wide-angle focal lengths of 21, 24, 28 and 35 mm. The practical focal length range offers both amateur and professional photographers a wealth of application potential, saving a time-consuming change of lens in many cases. The zoom also allows faster reactions to unexpected situations. The imaging quality of the LEICA VARIO-ELMAR-R f/3.54/21-35 mm ASPH. is equally convincing for photographs of people - including their immediate environment - as for landscape photographs with an impressive effect of depth.The high performance of the LEICA VARIO-ELMAR-R f/3.5-4/21-35 mm ASPH. is explained by its internal focusing design of 2 groups with 9 elements in 8 components. A concave aspherical element is used for the first time in this lens. This inward-curving, non-spherical shape poses a particular challenge for production technology. In technical terms, concave aspherical elements are new territory. Their production requires state-of-the-art computer-controlled measurement and engineering technology and also well-trained specialists with specific expertise, says Michael Thomas, Head of Optics Production. Focusing is performed by the first group, while the focal length is changed by simultaneously moving the two groups towards each other (35 mm) or apart (21 mm). The use of two aspherical lens surfaces, two elements of highly refractive glass and two with partial anomalous dispersion has resulted in a top-performance lens which is at the same time compact and light-weight.
Even at full aperture, the definition and contrast of the LEICA VARIO-ELMAR-R f/3.54/21-35 mm ASPH. are comparable with that of the corresponding fixed focal length lenses. Susceptibility to reflections is low for a wide-angle lens. The vignetting that is inevitable with short and very short wide angle lenses is only 1.3 stop in the corners of an image taken at full aperture and at 35mm focal length, or about 2 stops for the 21mm focal length setting. Even stopping down by 2-3 stops reduces the shadows significantly, so that they are only visible against uniform and pale backgrounds. The barrel-shaped distortion is also slight for a wide-angle zoom lens: approx. 1% for 35mm focal length, approx. 2% for 25 mm and approx. 3% for 21 mm. This means that it is negligible in practice, except at the shortest focal length setting and for critical subjects in this respect such as pictures of architecture.
Like the other Leica zoom lenses, the LEICA VARIO-ELMAR-R f/3.5-4/21-35 mm ASPH. also features a dual ring zoom, with which the focus and the focal length are set with separate rings (front and back, respectively). This design effectively prevents inadvertent maladjustment.
The LEICA VARIO-ELMAR-R f/3.5-4/21-35 mm ASPH. comes with a scalloped lens hood that is optimally matched to the light paths. Thanks to its symmetrical bayonet mount, it can be quickly and easily mounted the other way round to save space in the camera case.
Together with two other zoom lenses - the VARIO-ELMAR-R f/4/3570 mm offering standard focal lengths and the VARIO-ELMAR-R f/4/80-200 mm telephoto lens the LEICA VARIO-ELMAR-R f/3.5-4/21-35 mm ASPH. wide-angle zoom forms a complete set that offers excellent imaging performance and great ease of use.
The LEICA VARIO-ELMAR-R f/3.5-4/21-35 mm ASPH. with front and rear cap and bayonet lens hood in soft leather case is on sale now at Leica stockists'.