First to second generation tube converter for image intensifier - has size and terminals corresponding to tube to be changed and includes field lens

The conversion unit is for image intensifiers in which each optical path has an input objective, a three-stage first generation image amplifying tube of the type XX1211 with or without an integrated current supply, and an eyepiece. It converts to second generation tubes. The tube changing unit comprises a multichannel tube (12) at its input, an optical intermediate imaging unit (13), a field lens (14) at its output, and possibly a circuit (15) for current supply of the multichannel tube (12). Optical length, image scale and image rotation of the unit correspond to the values of the image amplifying tube (1) to be changed. The outer dimensions of the unit and its terminals correspond to those of the tube (1) to be changed.