NIKKOR Lens Glossary SIC: Nikon Super Integrated Coating ensures exceptional performance To enhance the performance of its optical lens elements, Nikon employs an exclusive multilayer lens coating that helps reduce ghost and flare to a negligible level. Nikon Super Integrated Coating achieves a number of objectives, including minimized reflection in the wider wavelength range and superior color balance and reproduction. Nikon Super Integrated Coating is especially effective for lenses with a large number of elements, like our Zoom-NIKKOR lenses. Also, Nikons multilayer coating process is tailored to the design of each particular lens. The number of coatings applied to each lens element is carefully calculated to match the lens type and glass used, and also to assure the uniform color balance that characterizes NIKKOR lenses. This results in lenses that meet much higher standards than the rest of the industry. AS: Aspherical lens elements Nikon introduced the first photographic lens with aspherical lens elements in 1968. What sets them apart? Aspherical lenses virtually eliminate the problem of coma and other types of lens aberration - even when used at the widest aperture. They are particularly useful in correcting the distortion in wideangle lenses. In addition, use of aspherical lenses contributes to a lighter and smaller lens design. Nikon employs three types of aspherical lens elements. Precision-ground aspherical lens elements are the finest expression of lens-crafting art, demanding extremely rigorous production standards. Hybrid lenses are made of a special plastic molded onto optical glass. Molded glass aspherical lenses are manufactured by molding a unique type of optical glass using a special metal die technique. CRC: Close-Range Correction system The Close-Range Correction (CRC) system is one of Nikons most important focusing innovations, for it provides superior picture quality at close focusing distances and increases the focusing range. With CRC, the lens elements are configured in a “floating element” design wherein each lens group moves independently to achieve focusing. This ensures superior lens performance even when shooting at close distances. The CRC system is used in fisheye, wideangle, Micro, and selected medium telephoto NIKKOR lenses. IF: Internal Focusing (IF) Imagine being able to focus a lens without it changing in size. Nikons IF technology enables just that. All internal optical movement is limited to the interior of the nonextending lens barrel. This allows for a more compact, lightweight construction as well as a closer focusing distance. In addition, a smaller and lighter focusing lens group is employed to ensure faster focusing. The IF system is featured in most NIKKOR telephoto and selected NIKKOR zoom lenses. N: Nano Crystal Coat Nano Crystal Coat is an antireflective coating that originated in the development of NSR-series (Nikon Step and Repeat) semiconductor manufacturing devices. It virtually eliminates internal lens element reflections across a wide range of wavelengths, and is particularly effective in reducing ghost and flare peculiar to ultra-wideangle lenses. Nano Crystal Coat employs multiple layers of Nikons outstanding extra-low refractive index coating, which features ultra-fine crystallized particles of nano size (one nanometer equals one millionth of a mm). Nikon now proudly marks a world first by applying this coating technology to a wide range of lenses for use in consumer optical products. VR: Vibration Reduction (VR) This innovative VR system minimizes image blur caused by camera shake, and offers the equivalent of shooting at a shutter speed three stops (eight times) faster.* It allows handheld shooting at dusk, at night, and even in poorly lit interiors. The lens VR system also detects automatically when the photographer pans - no special mode is required. * As determined by Nikon performance tests. ED: ED glass - an essential element of NIKKOR telephoto lenses Nikon developed ED (Extra-low Dispersion) glass to enable the production of lenses that offer superior sharpness and color correction by minimizing chromatic aberration. Put simply, chromatic aberration is a type of image and color dispersion that occurs when light rays of varying wavelengths pass through optical glass. In the past, correcting this problem for telephoto lenses required special optical elements that offer anomalous dispersion characteristics - specifically calcium fluoride crystals. However, fluorite easily cracks and is sensitive to temperature changes that can adversely affect focusing by altering the lens refractive index. So Nikon designers and engineers put their heads together and came up with ED glass, which offers all the benefits, yet none of the drawbacks of calcium fluorite-based glass. With this innovation, Nikon developed several types of ED glass suitable for various lenses. They deliver stunning sharpness and contrast even at their largest apertures. In this way, NIKKORs ED-series lenses exemplify Nikons preeminence in lens innovation and performance. RF: Rear Focusing (RF) With Nikons Rear Focusing (RF) system, all the lens elements are divided into specific lens groups, with only the rear lens group moving for focusing. This makes autofocusing operation smoother and faster. ML: Meniscus Protective Lens A curved meniscus protective glass element is installed in front of the lens to minimize ghosting by diffusing light re-reflected from the image sensor or film and the protective glass. Using a meniscus protective lens ensures a clear image with little ghosting. SWM: Silent Wave Motor Nikons AF-S technology is yet another reason professional photographers like NIKKOR telephoto lenses. AF-S NIKKOR lenses feature Nikons SWM which converts “traveling waves” into rotational energy to focus the optics. This enables high-speed autofocusing thats extremely accurate and super quiet. M/A: M/A mode AF-S NIKKOR lenses feature Nikons exclusive M/A mode, that allows switching from autofocus to manual operation with virtually no time lag - even during AF servo operation and regardless of AF mode in use. A/M: A/M mode (autofocus with manual override, AF priority mode) An “autofocus-priority autofocus” mode that reduces the sensitivity of the manual override to prevent unexpected switching from auto to manual. A-M: A-M switch An element that locks the focus ring during autofocus while enabling behavior similar to a manual focus lens in manual focus mode with sufficient load when the focusing ring is rotated. The focus rings on the AF-S DX NIKKOR 18-55 mm f/3.5-5.6G VR, AF-S DX Zoom Nikkor ED 18-55 mm f/3.5-5.6G, and AF-S DX Zoom-Nikkor ED 18-55 mm f/3.5-5.6GII rotate during autofocus. RD: Rounded Diaphragm Soft-focus shots of point light sources create regular polygonal shapes that reflect the shape of the opening created by the diaphragm blades. A rounded diaphragm uses blades designed to create a circular opening for a more beautiful soft-focus effect. D: Distance information D-type and G-type NIKKOR lenses relay subject-to-camera distance information to AF Nikon camera bodies. This then makes possible advances like 3D Matrix Metering and 3D Multi-Sensor Balanced Fill-Flash. Note: D-type and G-type NIKKOR lenses provide distance information to the following cameras: Auto exposure; F6, F5, F100, F90X, F80, F75, F70, F65, F60, F55, F50, PRONEA S, PRONEA 600i, D2 series, D1 series, D100 and D70s/D70. Flash control; F6, F5, F100, F90X, F80, F75, F70, D2 series, D1 series, D100 and D70s/D70. G: G-type NIKKOR The G-type NIKKOR has no aperture ring; aperture should be selected from camera body. DC: AF DC-NIKKOR lenses - unique NIKKOR lenses for unique portraits AF DC-NIKKOR lenses feature exclusive Nikon Defocus-image Control technology. This allows photographers to control the degree of spherical aberration in the foreground or background by rotating the lens DC ring. This will create a rounded out-of-focus blur that is ideal for portrait photography. No other lenses in the world offer this special technique. HRI: High Refractive Index lens With a refractive index of more than 2.0, one HRI lens can offer effects equivalent to those obtained with several normal glass elements and can compensate for both field curvature and spherical aberrations. Therefore, HRI lenses achieve great optical performance in an even more compact body. FL: fluorite lens Fluorite is a monocrystal optical material that features a high transmission rate within both the infrared and ultraviolet zones. With its superb anomalous dispersion properties, fluorite intensely blocks the secondary spectrum in order to effectively correct chromatic aberration within the visible light spectrum – something that is more difficult to achieve at longer focal lengths. It is also significantly lighter than optical glass, giving you a more effective lens with less weight. FC: fluorine coat Nikons fluorine coat effectively repels dust, water droplets, grease or dirt, ensuring easy removal even when they adhere to the lens surface. Thanks to Nikons original technology, it delivers higher durability and is more peel-resistant. Compared to other manufacturers coating of a similar kind, fluorine coat endures a higher frequency of lens surface wiping and provides longer-duration staying power. Its anti-reflective effect also contributes to the capture of clear images. Nikons fluorine coat is being applied first to the AF-S NIKKOR 400mm f/2.8E FL ED VR and AF-S TELECONVERTER TC-14E III. MTF Chart MTF (Modulation Transfer Function) is one of the measurements that evaluate a lens performance; it shows contrast reproducibility of the lens using characteristic spatial frequencies. Spatial frequencies indicate the number of lines per mm. In the MTF chart of this website, the horizontal axis is in millimeters and shows the distance from the center of the image toward the edges, and contrast value (highest value is 1) is shown in the vertical axis, with fixed spatial frequencies of 10 lines/mm and 30 lines/mm. The MTF chart for each lens is based on the value at the maximum aperture of the lens; the red line shows the spatial frequency of 10 lines/mm and the blue line, 30 lines/mm. In the off-axis field, contrast reproducibility of the lens for sagittal direction and meridional direction varies with astigmatic affection. The path of 10 lines/mm indicates the contrast reproducibility of the lens (the higher and straighter is better). The higher and straighter the 30 lines/mm-path is, the higher the resolution of the lens. Note that the lens performance can not be measured only with MTF chart. Softening or blurring of color also governs measurement.
Posted on: Mon, 01 Sep 2014 09:32:16 +0000
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