Scientific Photography and Applied Imaging

27 Low light level imaging

27.1 Introduction

A number of situations can be identified as presenting recording problems because the amounts of light (or radiation) concerned are of a very low level compared with conventional photography. This is often referred to as low light level photography or imaging, abbreviated to LLL or L³. Usually it is not possible to use supplementary lighting, but to rely solely on ambient conditions. A variety of detectors other than photographic materials are used. Human visual perception has well understood limitations in dim light, in that given sufficient time for suitable dark adaptation, monochromatic vision in starlight conditions is possible, albeit with low resolution (Rose, 1953; 1974). Figure 27.1 indicates ...