An imaging assembly in an imaging reader for electro-optically reading indicia includes a solid-state imager having an array of image sensors, and a focus control element, such as a liquid imaging lens, having a variable transfer function characteristics for capturing, optically modifying and directing return light from the indicia over a field of view onto the imager for processing into an electrical signal indicative of the indicia during a reading mode of operation; and a controller for controlling the imaging assembly to optically modify the return light in accordance with a known transfer function stored in a memory accessible to the controller during a calibration mode of operation prior to the reading mode.