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The 1950s also marked a time of notable development in the performance modeling of night vision imaging systems. From 1957 to 1958, Johnson, a United States Army Night Vision & Electronic Sensors Directorate (NVESD) [ 2 ] scientist, was working to develop methods of predicting target detection, orientation, recognition, and identification.
Night vision is of lower quality than day vision because it is limited in resolution and colors cannot be discerned; only shades of gray are seen. [1] In order for humans to transition from day to night vision they must undergo a dark adaptation period of up to two hours [ 2 ] in which each eye adjusts from a high to a low luminescence "setting ...
The sensitivity of a (digital or film) imaging system is typically described in the terms of the signal level that yields a threshold level of SNR. Industry standards define sensitivity in terms of the ISO film speed equivalent, using SNR thresholds (at average scene luminance) of 40:1 for "excellent" image quality and 10:1 for "acceptable ...
A specific type of NVD, the night vision goggle (NVG) is a night vision device with dual eyepieces. The device can utilize either one intensifier tube with the same image sent to both eyes, or a separate image intensifier tube for each eye. Night vision goggles combined with magnification lenses constitutes night vision binoculars.
LMS (long, medium, short), is a color space which represents the response of the three types of cones of the human eye, named for their responsivity (sensitivity) peaks at long, medium, and short wavelengths. The numerical range is generally not specified, except that the lower end is generally bounded by zero.
It is known that the rod cells are more suited to scotopic vision and cone cells to photopic vision, and that they differ in their sensitivity to different wavelengths of light. [ 2 ] [ 3 ] It has been established that the maximum spectral sensitivity of the human eye under daylight conditions is at a wavelength of 555 nm , while at night the ...
For example, binocular vision, which is the basis for stereopsis and is important for depth perception, covers 114 degrees (horizontally) of the visual field in humans; [7] the remaining peripheral ~50 degrees on each side [6] have no binocular vision (because only one eye can see those parts of the visual field). Some birds have a scant 10 to ...
An image intensifier or image intensifier tube is a vacuum tube device for increasing the intensity of available light in an optical system to allow use under low-light conditions, such as at night, to facilitate visual imaging of low-light processes, such as fluorescence of materials in X-rays or gamma rays (X-ray image intensifier), or for conversion of non-visible light sources, such as ...