An X-ray apparatus for image acquisition, comprising: an X-ray source (XR) configured to generate X-ray radiation for image acquisition of an object (PAT); a collimator (C) configured to collimate the X-ray radiation into a radiation cone, said radiation cone (PR) irradiating the object (PAT) at a region of interest when acquiring the image; a portable radiation detector (D), referred to herein as the detector (D), the said detector (D) configured to register the X-ray radiation after passage through the object, a field-of-view corrector (CS) configured to receive, in a pre-shot imaging phase, a scout image (SI) acquired by the detector with a tentative setting of the collimator (C), the pre-shot phase causing a low dosage radiation cone impinging on the detector, and the low dosage cone having in the detector's image plane a first cross section being smaller than a surface area of the detector, the field-of-view corrector (CS) being further configured to use said scout image to establish field-of-view correction information for a subsequent imaging phase, the field-of-view correction information including collimation correction information for determining a corrected setting of the collimator (C); wherein, in the subsequent imaging phase, a high dosage radiation cone is caused to imping on the detector, the high dosage being higher than the low dosage, and the corrected setting of the collimator ( C) causing the high dosage radiation cone to have, in the detector's image plane, a second cross section being larger than the first cross section, and the second cross section caused by collimation controller (CC) effecting movement of shutters (CB) of the collimator (C) based on the collimation correction information, and the second cross section being a symmetric enlargement of the first cross section and extending in its entirety within the surface area of the detector. an X-ray source (XR) configured to generate X-ray radiation for image acquisition of an object (PAT); a collimator (C) configured to collimate the X-ray radiation into a radiation cone, said radiation cone (PR) irradiating the object (PAT) at a region of interest when acquiring the image; a portable radiation detector (D), referred to herein as the detector (D), the said detector (D) configured to register the X-ray radiation after passage through the object, a field-of-view corrector (CS) configured to receive, in a pre-shot imaging phase, a scout image (SI) acquired by the detector with a tentative setting of the collimator (C), the pre-shot phase causing a low dosage radiation cone impinging on the detector, and the low dosage cone having in the detector's image plane a first cross section being smaller than a surface area of the detector, the field-of-view corrector (CS) being further configured to use said scout image to establish field-of-view correction information for a subsequent imaging phase, the field-of-view correction information including collimation correction information for determining a corrected setting of the collimator (C); wherein, in the subsequent imaging phase, a high dosage radiation cone is caused to imping on the detector, the high dosage being higher than the low dosage, and the corrected setting of the collimator ( C) causing the high dosage radiation cone to have, in the detector's image plane, a second cross section being larger than the first cross section, and the second cross section caused by collimation controller (CC) effecting movement of shutters (CB) of the collimator (C) based on the collimation correction information, and the second cross section being a symmetric enlargement of the first cross section and extending in its entirety within the surface area of the detector. <EOS>