How is magnification minimized in paralleling technique?

• A. Long PID (↑ Source-to-Object Distance)
• B. Short PID
• C. Move Receptor Away from Tooth
• D. Decrease Object-to-Receptor Distance

Answer: (A)

In paralleling technique, magnification is minimized by maximizing the distance from the X-ray source to the tooth. Using a longer PID increases the source-to-object distance, which reduces beam divergence at the tooth and results in less magnification on the image. A short PID would bring the source closer and enlarge magnification. Moving the receptor away from the tooth or reducing the object-to-receptor gap would also affect magnification, but paralleling technique already keeps the receptor as close as possible to the tooth, so the most effective and reliable adjustment is a longer PID.