A system comprising a confocal imaging apparatus comprising: an illumination module configured to generate an array of light beams; focusing optics comprising a plurality of lenses disposed along an optical path of the array of light beams, the focusing optics being configured to perform confocal focusing of the array of light beams onto a non-flat focal surface (230, 275, 310) and to direct the array of light beams toward a three dimensional object to be imaged, wherein the focusing optics lacks field lenses; a translation mechanism to adjust a location of at least one lens of the plurality of lenses to displace the non-flat focal surface along an imaging axis defined by the optical path; and a detector to measure intensities of an array of returning light beams (285, 472A-472C) that are reflected off of the three dimensional object and directed back through the focusing optics, wherein the system is configured to measure the intensities of the array of returning light beams for a plurality of locations of the at least one lens for determination of positions on the imaging axis of a plurality of points of the three dimensional object, and to adjust detected positions of one or more of the plurality of points to compensate for the non-flat focal surface, characterized in that the system further comprises a computing device including a field compensator which is configured to minimize or eliminate error introduced due to lack of the field lens, the computing device being further configured to: determine, for each returning light beam of the array of returning light beams, a location of the at least one lens that yields a maximum measured intensity; to determine, for each returning light beam of the array of returning light beams, a position on the imaging axis of a point of the three dimensional object illuminated by the returning light beam that corresponds to the determined location of the at least one lens; and to adjust the position on the imaging axis of the at least one point of the three dimensional object based on applying the determined location of the at least one lens to a field curvature model, to correct for changes in field curvature caused by changes in the focusing setting and/or changes in magnification caused by changes in the focusing setting, the field curvature model being calibrated to the confocal imaging apparatus to compensate for the non-flat focal surface. an illumination module configured to generate an array of light beams; focusing optics comprising a plurality of lenses disposed along an optical path of the array of light beams, the focusing optics being configured to perform confocal focusing of the array of light beams onto a non-flat focal surface (230, 275, 310) and to direct the array of light beams toward a three dimensional object to be imaged, wherein the focusing optics lacks field lenses; a translation mechanism to adjust a location of at least one lens of the plurality of lenses to displace the non-flat focal surface along an imaging axis defined by the optical path; and a detector to measure intensities of an array of returning light beams (285, 472A-472C) that are reflected off of the three dimensional object and directed back through the focusing optics, wherein the system is configured to measure the intensities of the array of returning light beams for a plurality of locations of the at least one lens for determination of positions on the imaging axis of a plurality of points of the three dimensional object, and to adjust detected positions of one or more of the plurality of points to compensate for the non-flat focal surface, characterized in that the system further comprises a computing device including a field compensator which is configured to minimize or eliminate error introduced due to lack of the field lens, the computing device being further configured to: determine, for each returning light beam of the array of returning light beams, a location of the at least one lens that yields a maximum measured intensity; to determine, for each returning light beam of the array of returning light beams, a position on the imaging axis of a point of the three dimensional object illuminated by the returning light beam that corresponds to the determined location of the at least one lens; and to adjust the position on the imaging axis of the at least one point of the three dimensional object based on applying the determined location of the at least one lens to a field curvature model, to correct for changes in field curvature caused by changes in the focusing setting and/or changes in magnification caused by changes in the focusing setting, the field curvature model being calibrated to the confocal imaging apparatus to compensate for the non-flat focal surface. determine, for each returning light beam of the array of returning light beams, a location of the at least one lens that yields a maximum measured intensity; to determine, for each returning light beam of the array of returning light beams, a position on the imaging axis of a point of the three dimensional object illuminated by the returning light beam that corresponds to the determined location of the at least one lens; and to adjust the position on the imaging axis of the at least one point of the three dimensional object based on applying the determined location of the at least one lens to a field curvature model, to correct for changes in field curvature caused by changes in the focusing setting and/or changes in magnification caused by changes in the focusing setting, the field curvature model being calibrated to the confocal imaging apparatus to compensate for the non-flat focal surface.