Elongation occurs when?

• A. Central Ray Perpendicular to the Receptor, Object Not Parallel
• B. Central Ray Perpendicular to the Receptor, Object Parallel
• C. Central Ray Perpendicular to the Object, Receptor Not Parallel
• D. Central Ray Perpendicular to the Object, Not Perpendicular to the Receptor

Answer: (D)

Elongation happens when the central ray is perpendicular to the object but not perpendicular to the receptor. In that setup, the object isn’t foreshortened, but tilting the receptor relative to the beam causes the projection of the object onto the receptor to appear longer than its true length. To avoid this distortion, keep the receptor parallel to the object and ensure the central ray is perpendicular to both; if the ray were perpendicular to the receptor while the object isn’t parallel, you’d get foreshortening.