Chromatic aberrations and color balancing issues with common optical axis CCD cameras

Abstract

Three-chip common-optical axis `beamsplitter' color cameras may seem complex, but they can provide image acquisition that is simultaneous in time and space, is perfectly registered, and covers 100% of three color bands--in other words, they deliver the `Holy Grail' of color imaging. Alternative schemes cannot match this feat, not can they match a good beamsplitter's image fidelity or ease of system integration. A common optical axis camera with integrated processing capabilities for color balancing offers even more advantages over the alternatives, as better color registration and uniformity result in reduced system, development and maintenance costs. The prisms associated with the beam splitter add a large path length of glass between a lens and sensor, and most systems are not designed to account for this altered path. To use a single lens the system should be optimized to compensate for the chromatic aberrations introduced by the various optical elements.