焦距

The factors for selecting the wavelength ranges to be measured are considered. The experiment equipment is introduced, with six key issues stressed, radiant power of light source should be higher, width of the I/O slits of the monochromator should be reasonable and both of them should be adjusted to an equal width, the focal length of the convergent lens should be longer, the exit of humidistat should be square, the function of vacuum pump and fog collecting hood is important, and the wavelength adjustment of the monochromator and the auto-record of the measuring signal should be controlled by a micro-computer.

讨论了实验中光波长范围的一些选择因素，详细介绍了实验装置，特别强调了实验装置中的6个要点：即光源的辐射功率要大；单色仪的出入射狭缝要合理且两者宽度应调成一致；会聚透镜的焦距要大；加湿器最后出口的孔必须是方的；真空泵和雾气收集罩的作用；微机控制单色仪波长鼓及测量信号的自动记录。

The longitudinal conjugated property of ideal optical system ;2. Starting from the principle of photograph formation by an ideal optical system , this paper derives the formulas of field depth and hyperfocal distance.

本文从理想光具组成像原理出发推导出景深和超焦距的公式，物理思想明确，并结合公式绘出了景深与有关参量的直观图，摄影者容易理解和掌握。

The hyperfocal distance of the EOS 10D is 1.6x less than that of a 35mm film camera when used with a lens giving the same field of view.

同样实际摄影，因为1.6x比35mm用同一距离便要支更短焦距的镜去影，令构图一致，所以1.6x有更深景深

Now high-end scanners are the focal length of automatic control, when you need a virtual Halo, also through the settings for color management software, to achieve the objective of the Elimination of moire, such as the IGC for the 370HS.

此刻矮端扫描仪是自不静把持焦距的调度，当必给虚晕时，也堵住色彩处置软件的撤销来调度，以到达打消龟纹的纲的，如ICG 370HS。

So we need to step out of our own heads and tune in.

所以我们要从自己的烦恼中走出来，对好焦距。

Stop Down: To decrease the diameter of the light-admitting orifice of a lens by adjustment of an iris diaphragm.

缩小光圈：镜头的焦距和光圈的有效直径之间的关系。一可调节的彩虹光阑，减少透镜光孔的直径。

Meassurement of the laser diode end-pumped solid laser′s thermal focal length by using the curve of output .

利用输出功率测量激光二极管端面抽运的固体激光器热透镜焦距。

This paper is the discussing about the aperture -coefficients of the Zoom Lens, the formula for the calculating is: F=f/d where.

该论文是探讨变焦镜头的光圈系数，镜头的光圈系数的计算公式：F=f/D(其中：F为光圈系数，f 为镜头焦距，D为光圈开口直径)。

Firstly,to abtain the parameters of coupling system,such as the focal length and the position of the lens,computing the Gaussian lens formula,then establishing the rectangular coordinate system and constructing equation and tracing the marginal ray to compute the parameter of the radius of the image beam waist.

首先使用高斯光束的透镜变换公式计算透镜的焦距及放置位置等耦合系统的参数，然后建立直角坐标系并利用耦合系统的参数构建方程，对边缘光线追迹，计算出像方束腰半径值。

In order to ensure the large focal length, the optical system, built according to the principle of the multiple internal reflection is used.

为了确保大焦距，光学系统，内置根据的原则多个内部反射的使用。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。