#
#   Plumbicon   Elcoma Philips
#
#   A. M. Dhake
#   TV and Video Engineering. 2nd edition.  1995
#   Figure 4.14,  page 65
#
Wavelength  Gray
400         218
420         245
440         265
460         278
480         281
500         279
520         265
540         231
560         180
580         105
600         55
620         25
640         5
660         0
