A confocal imaging apparatus includes an illumination module to generate an array of light beams. Focusing optics perform confocal focusing of an array of light beams onto a non-flat focal surface and direct the array of light beams toward a three dimensional object to be imaged. A translation mechanism adjusts a location of at least one lens to displace the non-flat focal surface along an imaging axis. A detector measures intensities of an array of returning light beams that are reflected off of the three dimensional object and directed back through the focusing optics. Intensities of the array of returning light beams are measured for locations of the at least one lens for determination of positions on the imaging axis of points of the three dimensional object. Detected positions of one or more points are adjusted to compensate for the non-flat focal surface.