• Metal PENTAX KAF Lens Mount• Equivalent focal length to 18.5mm-37mm in the 35mm format with *ist DSLRs• Extra-low Dispersion (ED) glass for superior sharpness and color correction• Responsive “Quick-Shift Focus System” allows instant shift from AF to MF• The image circle is designed to match the CCD used in PENTAX digital SLRs• Comes with a lens hood to minimize flare and ghost images