A control system for an imaging reader having an illuminating light assembly for illuminating a target with illumination light, and a solid-state image sensor with a rolling shutter for sequentially exposing an array of pixels to capture an image from the illuminated target , the control system comprising: an exposure controller for controlling an exposure time of the sensor ; a gain controller for controlling a gain of the sensor ; an illumination controller for controlling an output power of the illumination light; and a main controller operatively connected to the exposure, gain and illumination controllers , for maintaining the output power at a maximum level when at least one of the exposure time and the gain exceeds a minimum threshold, and for lowering the output power of the illumination light when the exposure time and the gain do not exceed the minimum threshold, while concomitantly maintaining the exposure time and the gain constant at the minimum threshold wherein the main controller is configured to calculate, based on determined brightness levels in at least two captured target images, a level of ambient light and a level of illumination light; wherein the main controller is further configured to determine whether or not the ambient light has affected the illumination light; and wherein the main controller is further configured to reduce the output power of the illumination light and the exposure time if it is determined that the ambient light has affected the illumination light. an exposure controller for controlling an exposure time of the sensor ; a gain controller for controlling a gain of the sensor ; an illumination controller for controlling an output power of the illumination light; and a main controller operatively connected to the exposure, gain and illumination controllers , for maintaining the output power at a maximum level when at least one of the exposure time and the gain exceeds a minimum threshold, and for lowering the output power of the illumination light when the exposure time and the gain do not exceed the minimum threshold, while concomitantly maintaining the exposure time and the gain constant at the minimum threshold wherein the main controller is configured to calculate, based on determined brightness levels in at least two captured target images, a level of ambient light and a level of illumination light; wherein the main controller is further configured to determine whether or not the ambient light has affected the illumination light; and wherein the main controller is further configured to reduce the output power of the illumination light and the exposure time if it is determined that the ambient light has affected the illumination light. a main controller operatively connected to the exposure, gain and illumination controllers , for maintaining the output power at a maximum level when at least one of the exposure time and the gain exceeds a minimum threshold, and for lowering the output power of the illumination light when the exposure time and the gain do not exceed the minimum threshold, while concomitantly maintaining the exposure time and the gain constant at the minimum threshold wherein the main controller is configured to calculate, based on determined brightness levels in at least two captured target images, a level of ambient light and a level of illumination light; wherein the main controller is further configured to determine whether or not the ambient light has affected the illumination light; and wherein the main controller is further configured to reduce the output power of the illumination light and the exposure time if it is determined that the ambient light has affected the illumination light. <EOS>