A longer than usual OID may cause which distortion?

A longer than usual OID may cause which distortion?

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

Answer: (D)

Magnification is driven by the geometric setup of the beam, object, and image receptor. When the object-to-image distance (OID) increases while the source-to-image distance (SID) stays the same, the object sits farther from the receptor and the projected image grows larger. The magnification factor M is essentially SID divided by SOD (with SOD = SID − OID), so increasing OID reduces SOD and increases M. That makes the image appear bigger—that's magnification. Elongation and foreshortening come from alignment or angulation issues, not simply a longer OID, and minification would occur if the object were closer to the receptor (smaller OID).

Magnification is driven by the geometric setup of the beam, object, and image receptor. When the object-to-image distance (OID) increases while the source-to-image distance (SID) stays the same, the object sits farther from the receptor and the projected image grows larger. The magnification factor M is essentially SID divided by SOD (with SOD = SID − OID), so increasing OID reduces SOD and increases M. That makes the image appear bigger—that's magnification. Elongation and foreshortening come from alignment or angulation issues, not simply a longer OID, and minification would occur if the object were closer to the receptor (smaller OID).