英语翻译GeneralAutofocus systems rely on one or more sensors to

英语翻译
General
Autofocus systems rely on one or more sensors to determine correct focus.Some AF systems rely on a single sensor,while others use an array of sensors.Most modern SLR cameras use through-the-lens optical AF sensors,which also perform as light meters.
The speed and accuracy of through-the-lens optical autofocusing is now often more precise than what can be achieved manually with an ordinary viewfinder.(More precise manual focus can,of course,be achieved with special accessories such as focusing magnifiers.) Autofocus accuracy within 1/3 of the depth of field (DOF) at the widest aperture of the lens is not uncommon in professional AF SLR cameras.
Most multi-sensor AF cameras allow manual selection of the active sensor,and many offer automatic selection of the sensor using algorithms which attempt to discern the location of the subject.Some AF cameras are able to detect if the subject is moving towards or away from the camera,including speed and acceleration data,and keep focus on the subject -- a function used mainly in sports and other action photography.
The data collected from AF sensors is used to control an electromechanical system that adjusts the focus of the optical system.A variation of autofocus is called an electronic rangefinder,a system in which focus data are provided to the operator,but adjustment of the optical system is still performed manually.
The speed of the AF system is highly dependent on the maximum aperture offered by the lens.F-stops of around f/2 to f/2.8 are generally considered optimal in terms of focusing speed and accuracy.Faster lenses than this typically have very low depth of field,meaning that it takes longer to achieve correct focus,despite the increased amount of light.Most consumer camera systems will only autofocus reliably with lenses that have a maximum aperture of at least f/5.6,while professional models can often cope with lenses that have a maximum aperture of f/8,which is particularly useful for lenses used in conjunction with teleconverters.

一般
自动对焦系统依靠一个或多个传感器确定正确的焦点.有些房颤的系统依靠单一传感器,而另一些人用一系列的传感器.大多数现代的单反相机使用through-the-lens光学心房颤动的传感器,也为光米.
在速度和准确度上现在through-the-lens光比通常更精确才能实现手动与普通的取景器.(更精确的手动对焦,当然可以获得特殊附件如聚焦放大镜.)自动对焦精度在1 / 3的深度(自由度)最宽的镜头光圈并不罕见的专业房颤单反相机.
大多数传感器的选择房颤允许手动相机的活跃的传感器,许多提供自动选择传感器算法,试图了解这个位置的主题.有些房颤摄像机可以检测是否走向或远离摄像机,包括速度和加速度的数据,并继续关注的主题——一个功能主要使用在体育和其他动作摄影.
通过传感器采集到的数据被用来控制一个机电系统调整重点的光学系统.一个变异的自动对焦称为电子测距仪,一个系统中数据集中的经营者,但调整的光学系统仍是手工完成.
心房颤动的速度是高度依赖系统提供了最大的光圈的镜头.F-stops f / 2的f / 2.8通常被认为是最优的对焦速度和精度.快镜头比这通常有很低的景深的,也就是说,它需要更长的时间来达到正确的焦点,尽管轻量的增加.多数消费者才会自动对焦相机系统可靠和透镜,有最大的缝隙中至少f / 5.6,而专业的模型可以经常应付透镜,有最大的孔f / 8,这是特别有用的镜片使用teleconverters.