At start-up (or on command), the D90 gives that sensor a little shudder to shake off dust that may have entered the camera during a lens change, in that way avoiding shadowy specks in the photos.

• 在开机启动时（或依设定），D90会轻微震动传感器以抖落更换镜头时进入的灰尘，避免了成像时可能出现的灰斑。