Improved ion mirrors 30 (FIG. 3) are proposed for multi-reflecting TOF MS and electrostatic traps. Minor and controlled variation by means of arranging a localized wedge field structure 35 at the ion retarding region was found to produce major tilt of ion packets time fronts 39. Combining wedge reflecting fields with compensated deflectors is proposed for electrically controlled compensation of local and global misalignments, for improved ion injection and for reversing ion motion in the drift direction. Fine ion optical properties of methods and embodiments are verified in ion optical simulations.