A train of air spaced optical mechanisms capable of taking a raw laser beam and focusing it on a workpiece for a range of cut sizes with varying magnifications and energy densities while controlling divergence and providing optimum uniformity. The lenses are diffraction limited for optimum uniformity and edge definition. The system uses variable down collimators to condense the beam to an aperture plane. The aperture is then imaged to the workpiece with Barlow, zoom transfer, collimator, and objective lenses. The components are color corrected to aid in alignment of an invisible beam and allow the aperture to be imaged to a workpiece in visible light.