Optical bandgap excitation can cause permanent or transient displacement of isolated ionic constituents in halide crystal lattices. The point defects that are formed can be utilized in some applications, but more generally they are detrimental to transmissive optics and dielectric films made from metal halide materials. The transient optical response to impulse excitation is the main subject of the work presented here. New measurements of defect formation with 2 ps resolution in KBr and RbBr are described. A survey of transient optical absorption from picoseconds to milliseconds is presented for alkali halides and partially for alkaline earth halides. This paper is intended to provide a basis for predicting the defect optical response of these materials to generation of electron-hole pairs, whether by multiphoton effects, direct ultra-violet absorption, or more conventional ionizing radiation.