reduces excessive bluishness in outdoor photographs size 54mm the hoya 77mm shmc skylight filter reduces the excessive bluishness that frequently occurs in outdoor color photography, especially in open shade under a clear, blue sky. the absorption peak is in the range which corresponds to the film's green spectrum. this means outstanding outdoor shots with superb color balance and clarity under all conditions. also keeps skin tones free of colored reflections from nearby objects such as the shade of trees. the hmc filters are renowned for their ability to minimise reflection at the filter surfaces which reduces flare and ghosting. the result is an average light transmission of over 97%, giving sharp contrast and well balanced color. hoya hmc filters are recommended for enhancing the performance of today's multicoated lenses. parallel imported warranty: warranty one year delivery within 2-4 business days