Methods of and systems for illuminating objects using planar laser illumination beams having substantially-planar spatial distribution characteristics that extend through the field of view of image formation and detection modules employed in such systems. In a pipelined ADC embodiment, for example, upstream converter stages are selected that generate an upstream digital code which defines sufficient upstream code words to designate respective segments of the inverse nonlinearity. Face detection focused on optimizing detection performance for each detecting mode is performed. The flow volume for aeration by the blower to the nitrification reactor is controlled such that the AB becomes 1.