A mass spectrometry apparatus uses image processing of output signals of a
camera in a mass spectrometer to provide feedback for directing the laser.
The present invention provides for the determination of where samples have
actually been deposited on a plate, and for the selection of different
points for each sample, based on its structure, at which to aim a laser,
during the cycle period of the mass spectrometer. Such feedback
information increases the likelihood that the laser impinges samples and
provides useful data.