Laser device, in particular for ophthalmological laser surgery, comprising - a laser source (14) to provide laser radiation, - controllable scanning components (20) to adjust a focus position of the laser radiation, - measuring components ( 30) for obtaining information, representative of a real position of the radiation source, - a control arrangement (22) that controls the laser source (14) and the scanning components (20), which is configured to effect carrying out a test cycle of at least a part of the scanning components with the laser source turned off according to a predetermined scanning scan pattern, the test scanning pattern defining at least one scanning path (32, 34) for the radiation focus and the control arrangement (22) being configured to perform during a sweeping motion along the scanning path several times consecutively a d Etection of the real focus position without stopping the sweeping motion and in association with each real focus position detected, determine a theoretical focus position, characterized in that the test scan pattern defines at least one scan path (32, 34) for the radiation source, which at least one point runs within the limit of a given maximum sweep field, which is limited by constructive specifications.Dispositivo láser, en particular para la cirugía láser oftalmológica, que comprende - una fuente de láser (14) para proporcionar radiación láser, - componentes de barrido controlables (20) para ajustar una posición de enfoque de la radiación láser, - componentes de medición (30) para la obtención de información, representativa de una posición real del foco de radiación, - una disposición de control (22) que controla la fuente de láser (14) y los componentes de barrido (20), que está configurada para efectuar la realización de un ciclo de prueba de al menos una parte de los componentes de barrido con la fuente de láser apagada según un patrón de barrido de prueba predeterminado, definiendo el patrón de barrido de prueba al menos
