A signal-to-noise-ratio parameter study and spectral analyses are performed on 1-% acetone/ 99%-air mixtures under different excitation conditions at a laser excitation wavelength of 266 nm. Signal-to-noise ratio is measured as a function of laser intensity, pressure, and camera read times. Comparison of spectral data is made with literature. The data collected in this paper is applicable in fluid diagnostics, such as velocimetry. The static pressure conditions of a high-speed shock tunnel were replicated, and the camera settings in the parameter study were the same as those typically used in previous velocimetry studies. An attempt was also made to re-excite an acetone photolysis species, using a 470 nm laser diode.