A detector and aperture determine radiation characteristics, including angular direction throughout a specified range, of external articles. Preferably an afocal aperture element enlarges/reduces the article and volume FOR. Mirror(s) along a path between detector and aperture, rotatable about plural axes, make the detector address varying regions. Preferably each mirror is MEMS, exceeding five to thirty microns. The detector "sees" articles throughout the range, at constant magnification. Other aspects rotate magnetically controlled dual-axis MEMS mirrors, each with electrical coils opposed across an axis, and anther magnet whose field interacts with coil-current fields, generating force components: one includes oppositely directed forces, torquing the mirrors; another thrusts mirrors outward from the array rest plane, causing variable "piston". Alternatively, other forces pull mirror(s) outward--and the second component attracts them inward. Components are adjusted to steer a beam in a desired direction, and wavefronts from adjacent mirrors are in phase for finer diffraction limit.