The introduction and extensive application of spectral shaping filters during fluoroscopic imaging procedures have decreased the patient skin entrance exposures (air kerma) dramatically while the image quality is optimized and maintained. The purpose of this article is to demonstrate and understand the functionality and operation of fluoroscopic automatic dose rate control logic installed on a modern cardiovascular angiography system, as seen from the equipment operation point of view. The fluoroscopic "patient" entrance exposure (air kerma) rate and the flat panel image receptor input exposure (air kerma) rate were obtained for reference and future application.