In conventional DSLR cameras, contrast AF is more accurate than phase difference AF, but it has a slower focus speed. LUMIX G/LEICA DG lenses overcome this problem by incorporating a unique stepping motor in the drive system. A screw unit integrated with the motor shaft moves the focus lens directly, without relay gears or cams. Auto focusing is swift and accurate. Some lens models are equipped with a linear motor to further reduce drive noise – ideal when recording videos with sound. The number of mount signal contacts has been increased from the 9 used in conventional Four Thirds System cameras to 11, so information transfer between lens and camera is faster. This has also helped achieve a contrast AF system that excels in both speed and accuracy.
Unlike image stabilizing functions that are built into the camera body, this highly accurate function also lets you check the compensation effect directly through the Live View Finder or on the LCD. The images that you capture have the same shake-free beauty as what you see on the Live View Finder or the LCD. The compensation effect is also carefully matched to each lens.
The Nano Surface Coating technology dramatically minimizes light reflection at entire visual light range (380nm-780nm) by applying the extra-low refractive index coating with nano-sized structure on the surface of the lens. It results in the super clear image with dramatic reduction of ghost and flare.
Utmost caution is exercised in coating the LUMIX G/LEICA DG lenses to suppress ghosts and flaring, while ensuring optimum color balance. In addition to a standard broadband anti-reflection coating, LUMIX G/LEICA DG lenses feature a coating that reduces the reflectance of light that enters at an angle. This multicoating process is widely used on lenses with a small radius of curvature, such as those in ultra-wide-angle lenses and fisheye lenses. It greatly improves the image rendering performance when shooting against a light source. Moreover, the bonded surfaces of cemented lenses are also given an original multicoating process to further reduce reflection. This results in high-quality images with superb clarity.
To assure superior image quality while reducing size and weight, each LUMIX G/LEICA DG lens features a number of aspherical lenses that effectively prevent lens aberration, such as spherical and distortion aberration. Each aspherical lens has the effect of several spherical lenses, so a higher magnification ratio can be achieved with fewer lenses. The result is smaller overall size and weight. Aspherical lenses are extremely difficult to produce, however, because they demand high dimensional accuracy. In the past this restricted the applicable lens shapes and materials, but Panasonic has made great strides in this area. Our Yamagata Plant began developing cutting-edge production technologies for molded lenses early on, and today the plant manufactures a wide variety of lenses – including concave lenses that have a large thickness difference and measure a mere 0.3 mm at the thinnest part. The aspherical lenses with superb image rendering ability produced at this plant now see widespread use.
In a conventional lens made only of optical glass, it becomes difficult to correct chromatic aberration when the focal length is long or the angle of view is wide, thus resulting in contrast degradation or color bleeding. This problem has been solved by Panasonic's Ultra Extra-Low Dispersion (UED / ED) lens. It suppresses the prism's color separation effect to correct longitudinal chromatic aberration at the telephoto zoom setting and chromatic difference of magnification at the wide-angle setting. The UED / ED lens is used mainly in LUMIX G / LEICA DG telephoto lenses and wide-angle zoom lenses to render sharp, high-contrast images with clear colors from corner to corner. The low dispersion of the UED lens, which is close to that of a fluorite lens, contributes to its superb imaging performance.
The LEICA DG SUMMILUX 25mm / F1.4 ASPH. adopts UHR (Ultra High Refractive Index) lens. Combined with glass mold aspherical lenses, the UHR index lens achieves uniformed description from the center to the edges.