Limitations in Optical Imaging Devices at Low Light-Levels

摘要

An examination is made of the influence of objective lens parameters on the resolution capabilities of low light-level imaging devices. From the resulting characteristics the dependence of the perception range of a given target on the incident light-level is deduced. The restrictions imposed by larger lenses on the depth-of-field of acceptable focus are investigated, and comparisons made with the thresholds set by quantum-noise and optical resolution limitations. Degradations in the performance of image-intensifiers due to different levels of image-tube darknoise are also discussed. (Author)