A novel underwater camera lens design is presented which replaces all interstitial air spaces with a low refractive index liquid to allow pressure compensation of the system in a thinner, safer diving package. The optical design presented overcomes the loss of refractive power by the liquid in a high performance, all spherical, f/1.2 lens, which operates over a 20-degree field of view. A design modulation transfer function of 0.85 is obtained at a typical CCD frequency of 50 1p/mm.