A bundle of drawn fibers that have X-ray scintillating unagglommerated nanocrystallite particles in plastic or glass cores of down to 0.1 micron spacing and claddings of X-ray absorbing compounds in the cladding composition. Optional is a cover to the bundle that blocks light from leaving the bundle at the X-ray side while allowing X-rays to pass into the cores. To image the light exiting the fiber bundle at the sub-micron level, light expansion is preferable using either a lens system or a fiber bundle expander.