Ghost images for optical systems with tilted object plane

Ghost images are formed by light that is partially reflected by optical surfaces. Ghost images may cause contrast reduction and may veil parts of the nominal image. Performing ghost image analysis during the design stage is important to ensure the success of the system. In a previous paper (Applied Optics, Vol. 50, Issue 15, pp. 2305-2315 (2011)), modeling ghost images was performed using a sequential ray tracing technique. Synthesizing ray paths into ghost and nominal paths and performing sequential ray tracing provides a powerful tool for describing ghost image formation in optical systems. We address the applicability of Scheimpflug principle for ghost image formation and we present a new criterion to identify problematic ghost images in the paraxial approximation. Numerical examples are considered and discussed.