Quality of the radiographic image
• Contrast
• Image geometry
• Characteristics of the x-ray beam
• Image sharpness and resolution
Perception of the radiographic image
• Partial images-we all see the same partial images but we don’t necessarily perceive the same object
• Contrast
• Context
Image geometry
• Positioning of the film, object and x-ray beam
• Focal spot size and principle of line focus
• Focal spot-object distance (FSOD), object-
to film-distance (OFD)
Focal spot size, heat distribution and image sharpness
• Focal spot 1mm
• Heat needs to be distributed over as large
as possible area
• Principle of line focus
FSFD
• Increasing the distance between the focal
spot and the object results in an image
with increased sharpness and less
magnification of the object
• Decreasing the distance between the
object and the film increases the
sharpness and result in less magnification
of the object