There is disclosed a video system having a photodetector for sensing an optical pattern that is representative of a field of interest. The system incorporates a CCD photosensor having a pixel format adapted to a particular video convention, and further includes video electronics, a video output device such as a display, tape, or computer, which is adapted to a second video convention. The video output device introduces a distortion into the system in accordance with an incompatibility between the first video convention and the second video convention. To correct the distortion a cylindrical lens is disposed in the optical path extending from the photodetector to the field of interest, for varying at least one dimension of the optical pattern.