问一下，CCD相机上的prepare gain reference 和 prepare dark reference 有什么区别，如果拍完照后，照片中间总是有一条黑线，应该调节哪个呢？哪位大侠知道呢？？作者: nsdm 时间: 2015-9-9 18:04
如果发现拍的图片有六方形的暗影或者图片有问题的时，点prepare gain reference ，样品远离观察视野，将光斑散开满屏，然后抬屏就可以点了
prepare dark reference，将荧光屏放下，使得CCD无光源信号，即可操作
说明文件的原文如下：
3.2. Prepare dark reference image
This section only applies to DualVision 600 CCD camera which do not have a TEM shutter control. The DualVision 600 camera is shutterless. Since CCD dark current depends upon the temperature, CCD must reach its set target temperature before acquiring the dark reference image. Before starting the preparation procedure, lower the TEM viewing screen (make sure no electron beam illuminates the CCD sensor during the procedure). Under the Camera menu, choose Prepare Dark Reference and follow the screen instructions.
3.3. Prepare gain reference image
It is important to prepare a new gain reference image after the CCD has reached the equilibrium temperature (normally this takes about 1 -2 hours). The gain reference image should be checked daily. To prepare gain reference image, remove specimen from the field of view, evenly spread the illumination across the CCD sensor; for wide angle CCD cameras, this could mean that the illumination is evenly spread across the entire viewing screen in the TEM. Under the Camera menu, choose Prepare Gain Reference. Set the target intensity to the value of about half the dynamic range. For example, for 14-bit cameras, set the value to 8000 and 12-bit camera to 2500. Normally it is sufficient to set the frames to average to 4. Then simply follow the instructions on the screen.作者: 小熊猫 时间: 2015-9-9 18:05 标题: 回复 #2 nsdm 的帖子
