The possibility of changing a resistor on the MOSCA video board to
bring the conversion factor of CCD W20 in line with the other three
was looked at. However, we do not have the type of resistors used
(chip resistors) and the value given on the circuit diagram is
inconsistent with the value expected and it is impossible to read the
value off the device, since it is only 1mm
2mm in
size. The main issue with having a different gain in one of the CCD is
that it is generally not possible to scale and display the mosaic
image as a whole as part of the image will appear complete white or
black. To get around this problem we are developing a post-processing
procedure that scales the mosaic image such that all quadrants/CCDs
are visible when displayed.