英语释义

• the distance from a lens to its focus

片语

focal aperture length焦距

focal-length extender[摄]

focal distance[光][摄] 焦距

focal l length ratio焦距比

focus焦点；中心；清晰；焦距

Focal distance length焦距长度

focal l length gauge焦距计

focal center length光心高度

focal aperture length calibration焦距检定

focal l length焦距

英汉例句

• for example, the focal length of an 8" (203.2mm) aperture with a focal ratio of f/10 would be 203.2 x 10 = 2032mm.

  比如，孔径为8英寸(203.2mm)，焦比为f/10的透镜，其焦距为203.2x10 =2032mm。

• the longer the focal length of the telescope, generally the more power it has, the larger the image and the smaller the field of view.

  一般来说，望远镜的焦距越长，它的放大率就越大，成像的尺寸就越大，但是视场范围就越小。

• the first shot was taken with a short focal length (around 70mm) and from a relatively close distance and the background looked quite far away and small.

  第一张焦距约70mm，在相对近的距离拍摄，背景看起来很远而且很小。

• the focal length is the most prominent aspect of a lens, because it dictates exactly how far you can zoom in or how wide you can pull back.

  焦距是镜头最显着的特征，因为它精确地控制你能将镜头推到多远，或你能将镜头拉到多近。

• digital slrs with a lens focal length of 300 to 400mm are recommended, but you can get away with a decent compact with a 10x zoom.

  推荐使用带有300-400毫米镜头的数码单反相机，但如果有一架有10倍变焦镜头，性能良好的小型相机也可以。

• to determine power, divide the focal length of the telescope (in mm) by the focal length of the eyepiece (in mm).

  将望远镜的焦距(单位:mm)除以目镜的焦距(单位:mm)，就可以得到望远镜的放大率。

• what excites ophthalmologists most, and what every lens-making company wants to achieve, is an 「accommodating」 lens that can change its focal length in the same way that a natural lens does.

  最让眼科学家兴奋的，而且每一家人工晶体制造公司都想获得的，是一种「善于适应新环境的」晶体，能像天然的晶体一样改变它的焦距。

• otherwise, set the focal length to infinity so that all distant objects are in focus.

  此外，把焦距设为无穷来保证所有远处的物体都被清晰对焦。

• if you know the focal ratio but not the focal length, you can calculate it: focal length is the aperture (in mm) times the focal ratio.

  如果你不知道焦距，只知道焦比(focalratio)，你可以通过这样计算的得到焦距：孔径(单位是mm)乘以焦比就是焦距。

• this can be a tedious process because the first time you create the plane, you have to rotate the camera and change the focal length at the same time to get a good match.

  这个过程可能很乏味，因为你要先建立平面，还不得不去旋转摄像机，并调节焦距以得到好的匹配效果。

• you also lose the focal length 「boost」 offered by smaller sensor cameras when shooting with telephotos.

  同时在摄远时长焦镜头给更小画幅相机带来的沖击力也会随之消失。

• using a longer focal length and photographing stars far from the north star increase the distance stars will move across the image.

  使用长焦镜头拍摄远离北极星的星星，会增加星星在相片上移动轨迹。

• set the focal length on your lens.

  给你的镜头设置焦距。

• camera lenses have two general attributes: f-stop and focal length .

  照相机镜头有两项一般属性：f制光圈和焦距。

• keep in mind that changing focal length will require refocusing in most zoom lenses.

  要注意的是，对于大多数变焦镜头来说，焦距改变了，就得重新对焦。

• or, you can calculate the exit pupil by dividing the focal length of the eyepiece (in mm) by the focal ratio of the telescope.

  或者，你还可以将目镜的焦距除以望远镜的焦比来得到出瞳尺寸。

• for example, a telescope with a focal length of 2000mm has twice the power and half the field of view of a 1000mm telescope.

  比如，与焦距为1000mm的望远镜相比，2000mm焦距望远镜的放大率和视场范围分别是前者的2倍和1/2。

• the reason for this is that as we know, longer focal length lenses magnify the image, but they also magnify the camera shake.

  正如我们前面所学，更长的镜头焦距虽然放大了图像，但同样增加了镜头抖动。

• for the first shot he used a shorter focal length and the second shot he used a longer one.

  先前的一张焦距短，第二张他用了长焦。

• but once you have the focal length determined, everything else is a piece of cake.

  但是，一旦你确定了焦距，其他事情就不值一提了。

• this is the ratio of the focal length of the telescope to its aperture.

  这是指望远镜的焦距与其孔径的比值。