thumb wheel

基本解释

The thumb wheel is used to set almost everything in the camera and it is tiny, slippery and hard to turn.
拇指滚轮用于设置在相机几乎一切，这是微小的，滑溜溜，难以转动。
Back focus adjustment is easy with the lockable thumb wheel, accessible from the top or bottom of the camera.
回到重点调整很容易与上锁的拇指滚轮，可从顶部或底部的相机。
The delay is a function of the heart rate, and can be corrected through thumb wheel switch within a large range.
延迟期随频率而变，另设有面板拨盘修正，可调范围大。

We never really found ourselves using the thumb wheel in our first-person shooters, but you can think of it as a two-way rotating programmable button if you will, and it spins in small enough increments to find use as a weapon or ability switcher.
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Key presses were comfortable and we're intrigued as to how the thumb-wheel module would fare once we got used to it.
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An active palm rest rounds out the modules, with a thumb-wheel and additional action button -- it's joined by a pair of (yet again) adjustable wrist rests that anchor along the bottom edge.
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