1. An improved optical reader for reading decodable indicia, comprising: a sensor that senses an excitation carrying information representing an encoded symbol and that provides an analog signal responsive to said excitation at an output terminal; an analog-to-digital converter configured to receive said analog signal from said sensor output terminal at an analog data input terminal, and to provide optimized digital data in an N-bit representation, where N is a positive integer greater than 1, said N-bit range of said analog-to-digital converter substantially spanning a dynamic range of said excitation as sensed by said sensor; and a microprocessor that manipulates said optimized digital data, thereby providing accurate decoding of said digital data under a range of illumination conditions.