An electron microscope and a method of imaging objects. The method including the steps of: generating at least one electron pulse, each electron pulse including a plurality of electrons with the electrons having a kinetic energy spread; demagnifying each electron pulse using one or more lenses, each lens having a focal strength; dynamically varying said focal strength of at least one of said one or more lenses to compensate for said kinetic energy spread; and forming an image of said object based on interactions at said object resulting from each demagnified pulse. The electron microscope comprising: an electron source adapted to produce a plurality of electron pulses, each electron pulse including a plurality of electrons with the electrons having a kinetic energy spread; one or more lenses adapted to demagnify each of said electron pulses at said object, each lens having a focal strength; compensation means for dynamically varying said focal strength of at least one of said one or more lenses to compensate for said kinetic energy spread; and a detector for forming an image of said object based on interactions at said object resulting from each of said demagnified pulses