Compact & lightweight " Pancake" type. Using glass-mold aspheric lenses at the 5th & 7th elements, is effective to in increasing the maximum aperture (5th element) & reducing the overall thickness of the lens (7th element). The final element, positioned as closely to the sensor as possible, makes the incidence angle of light reaching the sensor smaller, & reduces vignetting & color shading, while helping to keep the lens's overall size small.