Calibration sight (1) intended to geometrically calibrate an X-ray imaging device intended to generate three-dimensional images of an object by reconstruction from two-dimensional projections of said object, the calibration sight (1) comprising a volumetric support (20) provided with markers (10) with contrasting radiological absorption with respect to the volumetric support (20), the markers (10) being distributed according to a three-dimensional figure, characterized in that the markers (10) are distributed in subsets of markers distributed according to respective substantially parallel lines so that sequences of anharmonic relations can be constructed from the subsets of respective markers, each sequence of anharmonic relations comprising a single anharmonic relationship for each quadruple of markers in which the markers are arranged according to an order dependent on the order numbers n of the respective markers along the line according to which they are aligned according to a predetermined first direction, said order being common to all anharmonic relations, and when a subset of markers comprises at least five markers, the order of anharmonic relations in the sequences of respective anharmonic relations according to a predetermined rule common to all sequences of anharmonic relations, the sequences of anharmonic relations being all different.Mira de calibración (1) destinada a calibrar geométricamente un dispositivo de imagenología por rayos X destinado a generar imágenes tridimensionales de un objeto por reconstrucción a partir de proyecciones bidimensionales de dicho objeto, comprendiendo la mira de calibración (1) un soporte volumétrico (20) provisto de marcadores (10) con absorción radiológica contrastada con respecto al soporte volumétrico (20), estando los marcadores (10) distribuidos según una figura tridimensional, caracterizado porque los marcadores (10) están distribuidos en subconjuntos de marcadores distribuidos según rectas respectivas sustancialme
