A high performance, planar apochromatic, long-working-distance objective lens for Mitutoyo’s infinity corrected measuring microscopes and microscope heads. The long working distance provides excellent clearance between the lens and the workpiece surface, enabling observation of features that can be hard to view because of projecting features on the workpiece surface interfering with focussing and/or shadowing of the surface due to the proximity of ordinary objectives at high magnification. The apochromatic optical design provides a flat, chromatic-aberration-free image for true-colour viewing, making this objective an ideal choice for metallurgical applications.