Once everything is correctly set up, position the painting in front of the camera and experiment with the gain and offset settings on the Vidicon to achieve the optimum infrared image on the computer screen. Note that the appearance of the image on the computer will normally be different to its appearance on the video monitor connected directly to the camera.
Repeat this process at different points across the whole area to be captured. Although it is not always possible, the aim is to find a setting that does not need altering much during the capture of the data. This seems to lead to more successful mosaics.