prime focus observing capsule
/ˈpɹaɪm ˈfəʊkəs ɒbzˈɜːvɪŋ ˈkapsjuːl/
n
English · prime focus observing capsule中文 · 主焦点观测舱Español · cabina en el foco primarioFrançais · nacelle d’observation
Bedeutung：Area where astronomers once gathered to monitor the exposure time of photographic plates.