The variable-zoom method presented has a detector array with at least M*p pixels in each axis, where M is the maximum magnification and p x p is the size of the image array at each zoom. Pixels are binned based on the current magnification such that the final image size at each zoom magnification has a constant pixel array size. The fixed focal length imaging lens utilizes a variable aperture stop which is adjusted to maintain diffraction limited resolution. At low magnification the lens has a large field but requires lower resolution. As magnification increases the variable stop increases in size resulting in a smaller diffraction limited spot over a smaller FoV. The optical system can be much less complex than a traditional zoom and because there are no moving lenses, the image does not drift on the detector and there is no focal shift as the magnification changes. |
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