MIDI detector image

A typical MIDI detector image (life-size), given by the "field"camera mode of MIDI. The two disks correspond to the field-of-view of the two entrance beams (without beam-combiner before the detector), illuminated by the thermal background of the environment(walls of the laboratory). The vertical stripes correspond to the readout channels of the detector, which have slightly different gains,especially at the edge. Substraction by reference image allows to discard these artifacts.