focal-film distance

(redirected from Source-to-Image Distance)
Also found in: Acronyms.

fo·cal-film dis·tance

(FFD) (fōkăl film distăns)
The distance from the source of radiation (the focal spot of the x-ray tube) to the film or other image-receptor.
Synonym(s): source-to-image distance.

fo·cal-film dis·tance

(FFD) (fōkăl film distăns)
The distance from the source of radiation (the focal spot of the x-ray tube) to the film or other image-receptor.
Synonym(s): source-to-image distance.

focal-film distance,

distance

the measure of space intervening between two objects or two points of reference.

critical distance
focal-film distance
the distance between the anode of the x-ray tube and the film; an important exposure value.
flight distance
guard distance
interocclusal distance
the distance between the occluding surfaces of the maxillary and mandibular teeth with the mandible in physiological rest position.
interocular distance
the distance between the eyes, usually used in reference to the interpupillary distance (the distance between the two pupils when the visual axes are parallel).