The present disclosure relates to data readers including an improved imaging system that optimizes active and passive autofocus techniques for improving data reading functions. In an example, the data reader initially uses active autofocus techniques to focus a lens system based on a measurement reading by a rangefinder and acquire an image of an item in the field-of-view of the data reader. The data reader includes a decoding engine operable to decode an optical code of the item using the acquired image. If the decoding engine is unable to decode the optical code using the active autofocus technique, the data reader alternates to a passive autofocus technique to alter the focus settings of the lens system and reattempt the decoding process.