Anti-aliasing low-pass blur filter for reducing artifacts in imaging apparatus

An imaging apparatus ( 50 ) for generating an image signal from incident light with higher spatial frequencies of the incident light limited to reduce undersampling artifacts. Apparatus ( 50 ) includes a detector plane ( 62 ) for generating the image signal from an array of photosites, ( 63 ) and an optical section having a relatively thin lithium niobate rhomboidal filter ( 51 ) interposed in the path of the incident light so as to produce a blurred image on the photosites. A filter configuration is disclosed which produces four spots ( 58 ) at the imaging sensors ( 62 ) positioned at the corners of a rhombus.