For full swing commercially available 1/2" and 2/3" imaging sensors in standard
video cameras call for an illumination density of approximately 0.5 to 1.0 lx at
Improved sensitivities can be achieved by use of image intensifier tubes, coupled
to the CCD either fiberoptically or by relay lens. Such configurations are wellknown
at black and white low light level TV cameras.
Three-channel color cameras with three CCDs have to be equipped with three image
intensifier tubes intensifying each of the color component images (RGB) absolutely
free of geometric distortions. Such 3-channel low light level cameras are complex
in design and expensive.
The paper presents a low light level CCD color camera with only one chip and only
one image intensifier tube with an excellent cost/performance ratio. An absolutely
distortion-free proximity focus image intensifier diode PROXIFIER R of high
resolution with a color stripe filter beneath its photocathode is fiberoptically
coupled to a CCD with such a precision that the position of the filter-stripes
coincides with that of the vertical pixel rows of the CCD.