A versatile compact pancake lens a fast maximum aperture enables low light shooting and depth of field control stm provides smooth quiet autofocus when shooting video with compatible cameras extremely compact and portable design never be without your eos the compact pancake ef 40mm f28 stm is very thin so you will always be able to take your dslr with you smooth and quiet af stm focussing for movies fast accurate autofocusing ensures pin sharp images even in tough conditions movie s