Camera 0 rotation alignment

To align the specimen rotation axis with the camera center point, two images are recorded at 0° and 180° to take account of any eccentricity of the spindle with respect to the rotational center. The spindle is translated in x until the average of the coordinates of the location a, b or c, d is equal to the pixel value 511.5 at the center of the frame (Fig. 26.53). 

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