A mass spectrometer that employs ion velocity mapping. The mass spectrometer includes velocity mapping ion optics that focus the ions based on their velocity. The focused ions are then directed into a deflection region between two deflection plates. A pulse is applied to the deflection plates that deflect the ions in a transverse direction also according to their mass. The pulse is turned on before the first ion in an ion packet reaches the deflection region, and is turned off before the first ion exits the deflection region. The focused and deflected ions are then reflected by a reflecting device that directs the ions along separate paths to a detector. The detector provides an image of the ion paths, where the location of a spot on the image represents ions of a certain mass and the size of the spot indicates the various velocities of the ions of that mass.