Techniques developed to study the kinetics of very fast luminescent systems are described. These techniques include lamps which generate subnanosecond light pulses and an instrument which measures their time characteristics. The lamps are of the gaseous discharge type. The conditions of gas pressure, capacitance, and gap width necessary to achieve fast light pulses have been established for several gases and mixtures of gases with oxygen. The experimental results indicate that high pressure (10 atm or larger) and minimum stray capacitance are required for lamps filled with pure gas. A lamp filled with hydrogen, and satisfying these requirements, yields light pulses with 0.35 nsec risetime and 0.5 nsec half‐width. The time characteristics of the fast light pulses are not affected by gap width in the range 0.1–0.6 mm. Lamps containing a mixture of a gas and oxygen produce similar light pulses at total pressures much less than 10 atm. The instrument used to study subnanosecond light pulses employs a modified image converter tube. The image converter tube converts a light pulse into a photoelectron beam which is subsequently sampled by sweeping over an aperture. A complete intensity vs time curve is achieved by varying the time at which the sample is taken. The time resolution of the instrument is dependent on the sweep rate and the transit time spread of electrons in the image converter. Experimental and theoretical results indicate that the time resolution is around 0.1 nsec. The sweep is produced by a special circuit, consisting of a series of avalanche transistors, which generates sweep voltages around 600 V/nsec and can be triggered, with time jitter less than 0.2 nsec, by an electrical pulse as short as 1 nsec and amplitude of 0.8 V. This circuit makes it possible to measure the time characteristics of any light source for which a small electrical pulse can be generated simultaneous with the light pulse. A special detecting system which measures the intensity of the sample taken from the electron beam makes it possible to measure, with high precision, very low intensity sources. Thus, the time characteristics of a light pulse which produces less than one photoelectron per pulse at the photocathode of the image converter can be measured down to one decade of its peak intensity.