Device for taking an image having a body comprising an image intensifier tube having an optical axis (XX') and interacting with an image sensor, characterised in that the device for taking an image further comprises: a set of two interchangeable heads (11, 12), each of them having a field of view defined around a viewing axis (11.3, 12.3), the set comprising: one gamma head comprising a collimator (12.2) and a scintillator (12.1) for transforming a gamma ray coming from a gamma radiation source present in a scene and penetrating into the collimator (12.2) into an ultraviolet ray transmitted to the image intensifier tube; and one alpha head comprising a lens transparent (11.1) to ultraviolet radiation for transmitting an ultraviolet ray generated by an alpha ray coming from an alpha contamination source present in the scene to the image intensifier tube, the image intensifier tube being sensitive to the ultraviolet radiation coming both from the alpha head and the gamma head, and means for coupling the two heads of the set to the body one at a time, the coupled head (11 or 12) then having a viewing axis (11.3 or 12.3) coincident with the optical axis (XX') of the image intensifier tube so as to enable, for the gamma head, the ultraviolet radiation coming from the scintillator (12.1) to reach the image intensifier tube and, for the alpha head, the ultraviolet radiation that has traversed it to reach the image intensifier tube. a set of two interchangeable heads (11, 12), each of them having a field of view defined around a viewing axis (11.3, 12.3), the set comprising: one gamma head comprising a collimator (12.2) and a scintillator (12.1) for transforming a gamma ray coming from a gamma radiation source present in a scene and penetrating into the collimator (12.2) into an ultraviolet ray transmitted to the image intensifier tube; and one alpha head comprising a lens transparent (11.1) to ultraviolet radiation for transmitting an ultraviolet ray generated by an alpha ray coming from an alpha contamination source present in the scene to the image intensifier tube, the image intensifier tube being sensitive to the ultraviolet radiation coming both from the alpha head and the gamma head, one gamma head comprising a collimator (12.2) and a scintillator (12.1) for transforming a gamma ray coming from a gamma radiation source present in a scene and penetrating into the collimator (12.2) into an ultraviolet ray transmitted to the image intensifier tube; and one alpha head comprising a lens transparent (11.1) to ultraviolet radiation for transmitting an ultraviolet ray generated by an alpha ray coming from an alpha contamination source present in the scene to the image intensifier tube, the image intensifier tube being sensitive to the ultraviolet radiation coming both from the alpha head and the gamma head, and means for coupling the two heads of the set to the body one at a time, the coupled head (11 or 12) then having a viewing axis (11.3 or 12.3) coincident with the optical axis (XX') of the image intensifier tube so as to enable, for the gamma head, the ultraviolet radiation coming from the scintillator (12.1) to reach the image intensifier tube and, for the alpha head, the ultraviolet radiation that has traversed it to reach the image intensifier tube.