There can be small errors in rotation of the image sensors when they are soldered to the sensor board, as well as small rotation errors in the placement of the die within the sensor package. The accumulated error for these rotation variations is less than 1 degree. The value in the alignment file gives a positive (clockwise) or negative (counterclockwise) value to adjust the rotation of each sensor to match the master camera. Typical values range from +/- .05 degrees to +/- .50 degrees.