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Although digitalization has tripled consumer-class camera market scale, extreme reductions in prices of fixed-lens
cameras has reduced profitability. As a result, a number of manufacturers have entered the market of the System DSC
i.e. digital still camera with interchangeable lens, where large profit margins are possible, and many high ratio zoom
lenses with image stabilization functions have been released. Quiet actuators are another indispensable component.
Design with which there is little degradation in performance due to all types of errors is preferred for good balance in
terms of size, lens performance, and the rate of quality to sub-standard products. Decentering, such as that caused by
tilting, sensitivity of moving groups is especially important. In addition, image stabilization mechanisms actively shift
lens groups. Development of high ratio zoom lenses with vibration reduction mechanism is confronted by the challenge
of reduced performance due to decentering, making control over decentering sensitivity between lens groups everything.
While there are a number of ways to align lenses (axial alignment), shock resistance and ability to stand up to
environmental conditions must also be considered. Naturally, it is very difficult, if not impossible, to make lenses smaller
and achieve a low decentering sensitivity at the same time. 4-group zoom construction is beneficial in making lenses
smaller, but decentering sensitivity is greater. 5-group zoom configuration makes smaller lenses more difficult, but it
enables lower decentering sensitivities. At Nikon, the most advantageous construction is selected for each lens based on
specifications. The AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II and AF-S NIKKOR 28-300mm f/3.5-5.6G ED
VR are excellent examples of this.
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