geometric unsharpness


pe·num·bra

(pĕ-nŭm'bră) 1. radiology The blurred margin of an image. 2. radiation physics The region at the edges of a radiation beam over which a rapid change in dosage rate occurs.
Synonym(s): geometric unsharpness. [Mod. L., fr. L. paene, almost, + umbra, shadow]

pe·num·bra

(pĕ-nŭm'bră) 1. radiology the blurred margin of an image. 2. radiation physics the region at the edges of a radiation beam over which a rapid change in dosage rate occurs.
Synonym(s): geometric unsharpness. [Mod. L., fr. L. paene, almost, + umbra, shadow]