What is sharpness in a radiograph?

• A. The color depth of the image.
• B. How clearly a boundary between two different densities is shown.
• C. How bright the image appears.
• D. How quickly the exposure is completed.

Answer: (B)

Sharpness is about how clearly the boundary between two different densities is shown. A sharp image renders edges—like where bone meets soft tissue—in a crisp, well-defined way. It’s not about color depth (grayscale levels), brightness (overall exposure), or how fast the exposure happened. Sharpness is influenced by geometry and motion: a smaller focal spot, longer source-to-image distance, less object-to-image distance, and minimal patient movement all reduce blur and make edges crisper.