Image intensifiers (I.I.) are capable of detecting and amplifying low light level images and were primarily developed for night time viewing and surveillance under moonlight or starlight. They are used in industrial product inspection and scientific research, such as fluorescence microscopy. They are often combined with a Manufacturer of ccd camera to produce an intensified CCD (ICCD). For very low light levels I.I.s with two or three mcps can be used to create an image by detecting single photons. A high speed gate can be used with some image intensifiers to capture a fast event such as motion analysis of high-speed moving objects and fluorescence lifetime imaging.