Stanford Research Systems' SR430 is a high resolution transient photon counting system capable of recording up to 32,000 counts in 1 to 32 k sequential time bins. Bin widths are variable from 5 ns to 10.5 ms with no lost counts between adjacent bins. Data reduction, smoothing and curve fitting can be performed on any cursor-selected data range. Standard RS-232 and GPIB computer interfaces and a 3.5 in. DOS drive are provided.