Not all digital radiography systems allow an unrestricted image postprocessing for the radiologist. Depending on the X-ray system there are restrictions in varying brightness and contrast of the image. We compared grey level information that are given to the radiologist by various digital radiography systems. Histograms of differently postprocessed X-ray images were calculated, which were acquired by three different X-ray systems. We found that every modality has its own way of saving and converting the images into DICOM data. The processed image is either sent into PACS with the initial grey level range (10 or 12 bit) or the image is sent with a reduced grey level range due to windowing. The grey level range is associated with the ability of unrestricted windowing in PACS. So, taking an image with a reduced grey level range, the radiologist will face limited potential to optimise the window setting individually afterwards. The loss of image quality due to image transfer from the modality to PACS can lead to an information loss in the diagnostic relevant range.