a simple optical camera without a lens that projects an inverted image onto a surface through a tiny aperture

这种针孔摄影机展示了物理学中小孔成像的基本原理。

a miniature and concealable camera equipped with a pinhole-sized lens, commonly used for secret surveillance or illicit recording

酒店的浴室里发现了用来偷拍的针孔摄影机。