ED glass - an essential element of NIKKOR telephoto lenses
ED 玻璃: 尼康望遠鏡頭的一個重要元素
尼康發展出的超低色散玻璃(Extra-low Dispersion glass) 大大的降低了色差 使得尼康的望遠鏡頭成像銳利而且顏色真實
簡單的說 色差是來自不同波長的光進入玻璃時曲折角度不同而造成的 早期的望遠鏡頭為了矯正色差 必須加入一些氟化鈣晶體的透鏡來補償其他一般光學玻璃透鏡造成的光程角度差 但是氟化鈣有易碎裂的問題 而且其折射率受溫度影響很大 所以並不是最理想的解決方式
尼康的研發團隊投注了大量心血 發展出了數種ED glass 它特有的低色散特性大體消除了色差的問題 而且沒有氟化鈣的缺點 使用了ED glass 的尼康鏡頭即使在光圈全開時 依舊能產生銳利及高對比的影像 ED glass 可以說是尼康在鏡頭發展和創新方面登峰造極之作
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, NIKKOR's ED-series lenses exemplify Nikon's preeminence in lens innovation and performance.
Nikon Super Integrated Coating ensures exceptional performance
SIC 是尼康特別發展出來的多層透鏡鍍膜技術 它減低單片透鏡的反射率 所以對於透鏡數較多的變焦鏡頭非常重要 另外 對每一個透鏡的鍍膜 尼康都跟據該鏡頭的使用需求作整體的考量 使其達到最均勻平衡的顏色表現 遠超過業界的其他產品
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, Nikon's 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.
Nano Crystal Coat
奈米晶體鍍膜是多層的超低折射率 奈米大小顆粒塗佈於透鏡表面而成 1奈米=0.001微米=千萬分之一公分 (人髮的直徑大約不到100微米) 這個技術最早是在尼康的半導體機具上發展出來的 它大大減低透鏡的反射 所以對消除廣角鏡頭的內反射 鬼影 眩光 特別有效 尼康是第一個成功地將這種高科技的鍍膜技術導入一般光學產品的公司
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 Nikon's 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.
Aspherical lens elements
早自1968年尼康就在鏡頭裡使用非球面透鏡了 非球面透鏡的特點是即使鏡頭光圈全開 它仍能消除慧星相差 在超廣角鏡頭裡 它能大幅減低畸變(distortion) 再者 使用非球面透鏡可以減低鏡頭的體積和重量
精密研磨的非球面光學玻璃透鏡代表了透鏡工藝裡 難度最高 要求最嚴格的一個技術
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.
Close-Range Correction system
The Close-Range Correction (CRC) system is one of Nikon's 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.
Internal Focusing (IF)
Imagine being able to focus a lens without it changing in size. Nikon's IF technology enables just that. All internal optical movement is limited to the interior of the non extending 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.
Rear Focusing (RF)
With Nikon's 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.
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.
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.
The G-type NIKKOR has no aperture ring; aperture should be selected from camera body.
Silent Wave Motor
Nikon's AF-S technology is yet another reason professional photographers like NIKKOR telephoto lenses. AF-S NIKKOR lenses feature Nikon's SWM which converts "traveling waves" into rotational energy to focus the optics. This enables high-speed autofocusing that's extremely accurate and super quiet.
AF-S NIKKOR lenses feature Nikon's 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.
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.
Compact and lightweight DX NIKKOR lenses featuring a smaller image circle are specially designed and optimized for Nikon D2-series, D1-series, D100 and D70s/D70 digital SLR cameras. These are ideal options for landscape photographers and others who need to shoot expansive scenes with Nikon DX-Format digital SLRs.
Note: We do not recommend use of DX NIKKOR with 35mm (135) or IX240 format cameras.