ABSTRACT
The resolution may not be determined by the physical optics of the imaging lens, but by the mechanical structure or architecture of a focal plane array, or the cells and dots of photomechanical printing systems or by the Nyquist sampling limit. Photographic resolving power is the combined performance of lens plus film and other factors. The practical resolution limit is the limit of detail resolved by a lens as determined by resolution test charts, and is dependent on the contrast of the test subject as well as subjective factors. Lens resolution varies with aperture, wavelength and subject distance. The improved aberration performance and the degrading effects of diffraction are balanced together to give an optimum aperture for a lens. The optical image formed by a lens on the photo-cathode of an imaging tube is raster-scanned electronically so as to give a one-dimensional output signal variation with time, representing the two dimensional input image.
