The denser regions of sprays need to be probed in order to further understand the basic phenomena of the breakup of a bulk liquid into droplets and the subsequent drop dynamics. The instruments currently available to spray diagnosticians, the Malvern Spray Analyzer and the Phase Doppler Particle/Analyzer, cannot be used in the denser regions of the spray and in regions where ligaments or non-spherical droplets exist. Holography, as applied in the past, has allowed the interrogation of non-spherical drops, but in general has been applied to droplet dominated dilute regions of sprays. Using a focused-image holographic (FIH) system, with the advantages of an imaging lens and sidelighting, highly complex regions of sprays, such as those that include bubble explosions and complex ligament formation at the nozzle exit, can been probed. This paper presents
components of a FIH system for spray analysis, advantages and limitations of that system, and how the longitudinal magnification varies as a function of the length of the object along the optical path.