Setting of a low price CCD camera on the view window of TEM for printing out electron diffraction patterns

In order to print out electron diffraction patterns quickly, an industrial CCD camera is conveniently set on the view window of an electron microscope. Although the observed pattern on the camera is distorted since the view direction has an angle of 41.5 degrees from the normal of the screen, however, the printed pattern is successfully restored to the correct one by varying the aspect ratio from 3:4 for the CCD camera to 1:1 for the printer. Note that cos(41.5) = 3/4. The camera used has a sensitivity of 1 lux. The aperture ratio of the lens is F 1.4, and the focal length is 50 mm.