<prompt> While taking the bitewing film, the dentist should keep the direction and angulations of central ray:10 below the horizontal plane10 above the horizontal plane10 to the right10 to the left  <response>: The aiming cylinder is positioned about 10 degrees to project the beam parallel with the occlusal plane occlusal dentinoenamel junction. This orientation minimises the overlapping of the opposing cusps onto the occlusal surface and thus improves the probability of detecting early occlusal lesions at the dentinoenamel junction.Ref: ORAL RADIOLOGY Principles and Interpretation,Stuart C. White,Michael J. Pharoah Edition 7 page no 114 