A distance longer than intended for OID leads to which perspective change?

A distance longer than intended for OID leads to which perspective change?

• A. Elongation
• B. Foreshortening
• C. Minification
• D. Magnification

Answer: (D)

Geometric magnification is at play here. When the distance from the object to the image receptor (OID) is longer than intended, the X-ray beam spreads out more before reaching the receptor. If the source-to-image distance (SID) stays the same, the distance from the source to the object (SOD) decreases, which increases the magnification factor (M = SID / SOD). That makes the image on the receptor larger than the actual object—magnification. Foreshortening or elongation are distortions caused by the beam angle or the object’s orientation relative to the beam, not merely by a longer OID. Minification would occur if the geometry reduced magnification, which isn’t the case here.

Geometric magnification is at play here. When the distance from the object to the image receptor (OID) is longer than intended, the X-ray beam spreads out more before reaching the receptor. If the source-to-image distance (SID) stays the same, the distance from the source to the object (SOD) decreases, which increases the magnification factor (M = SID / SOD). That makes the image on the receptor larger than the actual object—magnification.

Foreshortening or elongation are distortions caused by the beam angle or the object’s orientation relative to the beam, not merely by a longer OID. Minification would occur if the geometry reduced magnification, which isn’t the case here.