Calumet 49mm Circular Polarising Digital SMC Filter Calumet's Super Multi-Coated filters are available in UV/P & Circular Polariser only. Calumet Digital Super Multi-Coated (SMC) filters are mounted in slim-profile rings to work with wider-angle digital lenses & are Super Multi-Coated for enhanced durability & superior light transition. Calumet Digital SMC filters have extra layers of multi-coating which result in an enhanced average light transmission of 99.7% & provide increased resistance to flare even at wide apertures.