Design and analysis of an 8x four-group zoom system using focus tunable lenses

We present an 8x four-group zoom lens system for a compact camera without any moving groups by employing a focus tunable lens (FTL). We locate the FTLs at the second and fourth groups as a variator and a compensator. In the initial design stage, paraxial analysis for the zoom position was numerically determined by examining the solutions for various first group and third group powers, to achieve a physically meaningful and compact zoom system at a zoom ratio of 8x. The designed zoom lens has focal lengths of 4-31 mm and the apertures of F/3.5 to F/4.5 at wide and tele positions, respectively.