focal plane shutter
/ˈfəʊkəl ˈpleɪn ˈʃʌtə/
n
English · focal plane shutter中文 · 焦平面快门Español · obturador de plano focalFrançais · rideau d’obturateur
意味：Opaque device that opens for a predetermined length of time based on the shutter speed chosen; it allows light to come in contact with the film.