The Pentax SMC-DA* 16-50mm f/2.8 ED AL IF SDM lens was designed for Pentax DSLRs with APS-C size sensors. It houses the Quick-shift focus motor and supersonic motor for fast and smooth autofocusing. The lens has 24-75mm equivalent field of view with a fast f/2.8 max aperture that is consistent throughout the zoom range. Its lens construction consist of 15 elements in 12 groups, nine aperture blades, 11.81" minimum focusing distance, SP coating for easy cleaning while repelling moisture, dust, and oil base substance, and employs Pentax's weather-resistant chassis. The SMC-DA*16-50mm SMC ED AL IF offers a striking image quality and is designed for photographers who wish to go beyond with top-notch performance.