The microfocal X-ray unit is a constant-potential X-ray generator with a 10–60 kV range and delivering a 1 mA current. The continuously evacuated X-ray column comprises two electromagnetic lenses which throw a greatly reduced electron image of the cathode onto the side of a solid, oil cooled, tungsten target. At 60 kV, 1 mA, the X-ray source size is approximately 6 μm in diameter, the smallest known to date. The object is brought close to the source to obtain high direct magnification up to × 15 within a short camera. The use of rare earth screen/film combinations (Trimax α 16 and α 8) have reduced the exposure times. Noise inherent in these systems is overcome with magnifications of × 3 or more. Phantoms containing grids show that the resolution increases with magnification providing a resolution of 25 μm at × 9.