B+W POLFILTER HIGH TRANSMISSON ZIRCULAR MASTER KSM MRC nano 77 mmIn these high-end polarizing filters, the polarizing film is more tightly specified and the film pieces are specially selected.After cementing between high-quality cover glasses, an additional grinding and polishing process takes place.This ensures superior sharpness even with very fast, apochromatic lenses. The cementing technique ensures long-term stability even in humid climates.The generation of Käsemann High Transmission (HTC) polarizing filters is designed with a polarizing film that has a higher light transmission (transmission) and still has an excellent efficiency.The filter extension factor is only 2 - 3 which corresponds to approx. 1 - 1.5 f-stops.