渐晕

A difference emerges with the fact that the IOR shows some vignetting, which is not there in the DF. The reason is that the DF employs larger prisms, which enable it to fully illuminate the 60 degs. field of view.

不同之处是IOR表现某些渐晕，DF没这现象，原因是DF拥有更大的棱镜，能完全照亮60度视场，另一方面，DF更大更重。

2According to requirement of suppressing stray light in two-mirror system, vertex coordinate formulas of inner baffle are deduced based on geometrograph in the case of certain obscuration, viewing field and vignetting. In order to reduce the obscuration, conical baffle of secondary mirror is ameliorated into a shutter one. Outer baffle is designed when angle of stray light suppressing is foregone and the vanes are designed in C-language program. Finally, the same-height vanes in drawtube between primary and secondary mirrors are designed for further suppressing the stray light in two-mirror system.

给出双反射系统杂散光消除设计的具体要求，结合作图法，推导出考虑视场大小及初始中心遮光比确定时，主次镜内遮光罩顶点坐标公式；讨论考虑渐晕时主次镜内遮光罩的设计；为了减小初始中心遮光比，将次镜锥状遮光罩改进为百叶窗式结构；设计在杂散光源抑制角已知时的外遮光罩，并利用C语言实现程序化设计其挡光环的方法；设计主、次镜间镜筒内壁上等高挡光环，进一步抑制双反射系统的杂散光。

In this paper, the research on vignetting is done and a formula for vignetting about field angle、entrance window, entrance pupil and the distance between them is deduced.

文中对渐晕做了一些研究，并推导出一个渐晕关于视场角、入瞳、入射窗以及两者之间距离的解析式。

The image quality of the zoom lens is improved, and the maximum FOV vignette is avoided.

设计结果表明：该镜头克服了普通镜头水下使用像质变差和最大视场渐晕等缺点。

Due to the problem that the relative parameters of aviatic sensing image are often difficult to get, A line scan and data fitting method was presented in order to obtain whole gray change in image, and then to correct image vignetting phenomenon.

针对航空遥感影像在拍摄过程中相关参数不易获取的问题，提出了利用逐行扫描及数据拟合的方法来获取影像整体灰度变化情况，从而实现影像渐晕现象的复原。

Considering the particularity of bar code scanning system, a new method to analyze the intrinsic vignetting effect of retroreflective collection system with the help of computer graphics is proposed and has been used to optimize the optical system configuration.

为了得到尽可能高的信噪比，提出采用回向接收方案来限制接收系统的瞬时视场。针对条码扫描系统的特点，提出了一种利用计算机交互技术和图形技术来分析此回向接收系统渐晕特性的新方法。

Meanwhile a new method to compute the vignetting coefficients has been given.

文章同时给出了计算渐晕系数的新方法。

Vignetting has to be on strong for the stripe options to work .

渐晕，必须强有力的条纹选择工作。。。

Can be pushed back to prevent vignetting.

可以推后，以防止渐晕。

Vignetting is a classic photography technique involving darkening areas of an image in order to focus the viewer's attention on a desired point of interest.

渐晕是一个典型的摄影技术，涉及的图像变暗领域，以便集中所需的兴趣点，观众的注意。

We are in a real jam.

我们的麻烦大了。

Hey, it's Ahmet from India, that foreign exchange guy.

看，那是印度的阿曼特，国际交换生