Aperture effect

This phenomenon is existing in the imaging process and is also present during the imaging process. As an example of imaging, it is specifically that since the electrical signal of the scanning electron beam spot is the average value of the extracted physical detail spot, when the scanned electrical signal spot and the physical details are in size. Almost, if the scanning electron beam is swept away from the other black and white adjacent real thing, the electron beam is just on the physical detail spot, so it can truly reproduce the mutant boundary of the black, white light point, maintain high Horizontal clarity; in contrast, if the scanning electron beam sweeping is not two black and white adjacent spot itself, but the edge, at this time, it is not possible to reproduce the boundary of the black and white mutation of the spot, but reproduce one. The boundaries of the bright and dark transitions thus becomes blurred, causing the image level sharply, and the degree of decline is 50%. From the statistical law, it has 50% of the possibilities of 50% on the boundary of the spot and just sweeping the spot. In this way, 50% area has maintained the original definition; 50% of the area has only half, that is, 25% of the total definition of the original image. Therefore, the last 50% and 25% clarity of the entire image is added, which is equivalent to 75% clarity.